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PubMed1996

Prostate volume predicts outcome of treatment of benign prostatic hyperplasia with finasteride: meta-analysis of randomized clinical trials.

OBJECTIVES: Six randomized clinical trials have compared at least 1 year of 5 mg finasteride to placebo in the treatment of clinical benign prostatic hyperplasia (BPH). The findings for the 2601 men in these trials provide an opportunity to investigate the heterogeneity of the effects seen in the individual studies and to identify pretreatment predictors of outcomes as expressed by symptoms or peak urinary flow rates. METHODS: A formal meta-analysis using an Empirical Bayes approach employed data from all finasteride studies which included the Phase III trials in North America and Internationally, the Prospect, Early Intervention, and SCARP trials, and the Veterans Administration Cooperative Study which compared terazosin, finasteride, and the combination of these two drugs. A pooled analysis was also undertaken on the combined dataset. RESULTS: The effect of finasteride treatment on improvements in total symptom severity, frequency score, and peak urinary flow rate was consistent across all six trials and similar among men with similar prostate volumes at baseline. Symptom severity improved by 1.8 points (95% confidence interval [CI], 0.7 to 2.9) in men with prostate volumes less than 20 cc (n = 72), while the improvement was 2.8 points (95% CI, 2.1 to 3.5) for men with volumes greater than 60 cc (n = 272) on the Quasi-IPSS Scale (range 0 to 30). Similarly, improvements in peak urinary flow rate ranged from 0.89 mL/s (95% CI, -0.05 to 1.83) for men with prostate volumes less than 20 cc to 1.84 mL/s (95% CI, 1.37 to 2.30) in men with volumes greater than 60 cc. The difference in the magnitude of improvement between finasteride and placebo becomes significant (that is, no overlap in 95% CI) for men with a baseline prostate volume assessed by either transrectal ultrasonography or magnetic resonance imaging of greater than 40 cc, which encompasses approximately 50% of the entire population. Baseline prostate volume is a key predictor of treatment outcomes: approximately 80% of the variation in the treatment effects noted between studies could be attributed to differences in mean prostate volumes at baseline. Variation in entry criteria results in large differences in baseline symptom severity status, prostate volume, and consequently apparent inconsistencies in the overall outcomes of these trials. CONCLUSIONS: This meta-analysis suggests that finasteride is most effective in men with large prostates. Men with small prostates may not be suitable candidates for finasteride therapy for BPH. The need for a careful reevaluation of the definitions and terminology used when discussing urination problems is apparent.

Enzyme Inhibitors↗

PubMed2004

Interferon beta-1b in secondary progressive MS: a combined analysis of the two trials.

BACKGROUND: A European (EU) and a North American (NA) placebo-controlled study with interferon beta-1b (IFNB-1b) in secondary progressive multiple sclerosis (SPMS) showed divergent results with regard to their primary outcome of sustained Expanded Disability Status Scale (EDSS) progression, while effects were similar on relapse and MRI-related endpoints. Reasons for this discrepancy were explored in the combined dataset. METHODS: Baseline characteristics and variability in EDSS assessments were compared. Retrospective combined analyses for time to confirmed progression were performed to assess treatment effects overall and in subgroups defined by pre-study disease activity criteria and other key baseline variables. RESULTS: The variance of EDSS measurements was 6.5% higher in the NA-SPMS study. The EU study included patients in an earlier phase of SPMS and with more active disease both pre-study (relapses, MRI) as well as on study (EDSS, relapses, and MRI variables as assessed in the placebo groups). The pooled analysis showed an overall risk reduction by about 20% in patients treated with 8 MIU (250 mcg) IFNB-1b for EDSS progression confirmed at 6 months (p = 0.008). Risk reduction by 30% to 40% was found for patients with at least one relapse or change in EDSS by >1 in the 2 years prior to study entry. No other consistent across-studies relation of clinical and MRI variables at baseline to potential treatment response was found. CONCLUSIONS: Although post hoc, this combined analysis of the two large studies with IFNB-1b in secondary progressive multiple sclerosis suggests that both pronounced disability progression and continuing relapse activity might help in identifying those patients in the secondary progressive phase of the disease who are more likely to benefit from treatment.

Adult↗

PubMed2002

Sustained ventricular arrhythmias among patients with acute coronary syndromes with no ST-segment elevation: incidence, predictors, and outcomes.

BACKGROUND: The prognosis of ventricular arrhythmias among patients with non-ST-elevation acute coronary syndromes is unknown. We studied the incidence, predictors, and outcomes of sustained ventricular arrhythmias in 4 large randomized trials of such patients. METHODS AND RESULTS: We pooled the datasets of the Global Use of Streptokinase and tPA for Occluded Arteries (GUSTO)-IIb, Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT), Platelet IIb/IIIa Antagonism for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network (PARAGON)-A, and PARAGON-B trials (n=26 416). We identified independent predictors of ventricular fibrillation (VF) and ventricular tachycardia (VT) and compared the 30-day and 6-month mortality rates of patients who did (n=552) and did not (n=25 864) develop these arrhythmias during the index hospitalization. Independent predictors of in-hospital VF included prior hypertension, chronic obstructive pulmonary disease, prior myocardial infarction, and ST-segment changes at presentation. Except for hypertension, these variables also independently predicted in-hospital VT. In Cox proportional-hazards modeling, in-hospital VF and VT were independently associated with 30-day mortality (hazard ratio [HR], 23.2 [95% CI, 18.1 to 29.8] for VF and HR, 7.6 [95% CI, 5.5 to 10.4] for VT) and 6-month mortality (HR, 14.8 [95% CI, 12.1 to 18.3] for VF and HR, 5.0 [95% CI, 3.8 to 6.5] for VT). These differences remained significant after excluding patients with heart failure or cardiogenic shock and those who died <24 hours after enrollment. CONCLUSIONS: Despite the use of effective therapies for non-ST-elevation acute coronary syndromes, ventricular arrhythmias in this setting are associated with increased 30-day and 6-month mortality. More effective therapies are needed to improve the survival of patients with these arrhythmias.

Acute Disease↗

PubMed2006

Correlation of intercondylar notch cross sections to the ACL size: a high resolution MR tomographic in vivo analysis.

INTRODUCTION: To correlate cross sections of the intercondylar notch to cross sections of the anterior cruciate ligament (ACL) and to analyze gender-related differences in notch and ACL morphometry with an attempt to explain the observation that a small intercondylar notch and the female gender predispose to a rupture of the ACL. MATERIAL AND METHODS: High resolution MR imaging was performed on a 1.5 T magnet using a dedicated extremity-coil in ten left and ten right knee joints of 20 volunteers (10 male, 10 female, mean age 25 years) with no history of knee abnormalities. Continuous axial T2-weighted MR images perpendicular to the longitudinal axis of the ACL were acquired. Cross-sectional areas of the ACL midsubstance at the contact area to the posterior cruciate ligament were measured. For imaging and evaluation of the osseous limits of the intercondylar notch a 3D-dataset of the knee was acquired. Anterior, middle and posterior planes of the intercondylar notch were calculated and analyzed for measurement of the notch area AN and notch width index NWI. The ratio of the ACL cross-sectional area of the ACL and the cross-sectional area of the notch was defined as the ACL notch index (ANI) and used as a standardized tool for evaluation. For statistical evaluation, linear regression analysis was performed. Mean values between male and female were compared using a t test. In addition, five matched pairs of male and female volunteers of same height were analyzed. RESULTS: Mean cross-sectional size of the ACL at the crossing with the PCL was 54.4 +/- 20.4 mm2. Regression analysis showed a significant correlation (P < 0.05) of the ACL cross-sectional area to the notch areas on all three planes and NWI, respectively. Comparison between the sexes revealed that female participants had significantly smaller cross-sectional areas of the ACL, the notch areas, the NWI and ANI. This difference was found for both the complete study group and the matched pairs of same height. CONCLUSIONS: The smaller the intercondylar notch the smaller the cross-sectional area of the ACL midsubstance. In addition to the impingement of the ACL at the anterior and posterior roof of the notch, a biomechanically weaker ACL may be the reason for disposition to an ACL rupture in patients with a small intercondylar notch. Women have a thinner ACL midsubstance than men of the same height which may be one of the critical etiologic factors that predispose women to an ACL rupture.

Anterior Cruciate Ligament↗

PubMed2004

Population pharmacokinetics of APOMINE: a meta-analysis in cancer patients and healthy males.

AIMS: 1) To characterize the population pharmacokinetics of apomine in healthy males and in male and female patients with solid tumours and 2) to understand more fully the influence of induction and between- and within-subject variability on exposure to drug using Monte Carlo simulation. METHODS: Apomine was administered once- or twice-daily with or without food in single and multiple oral doses of 30-2100 mg to healthy males (n = 19) and patients with solid tumours (n = 19). The data were divided into model development and validation sets. Models were developed using standard population methods. These were the identification of an appropriate base model, calculation of the empirical Bayes estimates of the primary pharmacokinetic parameters, covariate screening, forward stepwise addition of covariates using the likelihood ratio test as a model selection criteria, and backwards elimination to obtain the final model. To study the influence of data from individual subjects, the model development dataset was subjected to the delete-1 jack-knife and the final model was fitted to each jack-knifed dataset. Principal components analysis of the jack-knifed matrix of model parameters identified two influential subjects who were removed from the dataset, and the final model contained data from the remaining subjects. Model validation was examined using goodness of fit statistics and relative error measures using independent datasets from cancer patients. The model provided a reasonable approximation to the pharmacokinetic measurements in the validation datasets. Computer simulations were undertaken to understand further the pharmacokinetics of apomine in otherwise healthy females, a population not yet studied. RESULTS: Apomine pharmacokinetics were complex and consistent with a two-compartment model with a lag-time. Apparent oral clearance at baseline and apparent volume of distribution at steady-state were larger in healthy males than in cancer patients (41 ml h(-1) and 14.1 l vs 10 ml h(-1) and 8.9 l, respectively, for a 75 kg person). Clearance was time-variant showing a maximal increase with full induction of 320 ml h(-1), independent of patient type. The time to reach 50% maximal induction was about 2 days. The fraction of drug absorbed was relatively constant at doses less than 100-200 mg once daily but decreased at higher doses. Food also decreased relative bioavailability by 36%. Patient characteristics had no effect on apomine pharmacokinetics except for weight, which was proportional to the volume of the central compartment. Between-subject variability (68% for clearance, 30% for central volume, and 141% for peripheral volume) was moderate to large and independent of patient type. Inter-occasion variability was small (18% for both clearance and central volume). Residual variability was modelled with an additive and proportional error model. Cancer patients had slightly higher plasma concentrations than healthy males but this difference was probably not clinically significant. Steady-state was reached in about 3-4 days after once-daily drug administration. The half-life of apomine after three weeks of once-daily dosing was 41 h in cancer patients and 32 h in healthy males. CONCLUSIONS: A population model for apomine has been developed has been developed that characterizes its pharmacokinetics in cancer patients and healthy subjects under a variety of conditions.

Adolescent↗

PubMed2026

Eligibility of real-world patients for aspirin primary prevention trials in cardiovascular disease.

BACKGROUND: Evidence for the net benefit of aspirin for primary prevention of cardiovascular disease (CVD) is finely balanced, leading to variation in guideline recommendations internationally. External validity of randomised clinical trial (RCT) evidence may therefore be of particular importance. The aim of this study is to characterise real-world patients according to their eligibility for guideline-cited aspirin RCTs for primary CVD prevention. METHODS: Eligibility criteria from 14 RCTs were applied to a linked primary care/hospital discharge dataset of people ≥ 40 years without CVD. Proportions eligible for each trial were calculated, and characteristics of eligible and ineligible patients compared for each trial, including Cox regression analysis of event rates for major adverse cardiovascular events (MACE), major bleeding events, and non-cardiovascular mortality. RESULTS: Of 570,211 included patients (300,500 [52.7%] women, 336,877 [59%] < 60 years), the median proportion ineligible for 14 RCTs was 90.7% (range 42.5-99.4%) and 24.0% of patients were ineligible for all RCTs. On average, trial-ineligible populations were younger (median age trial-ineligible 57.8 vs trial-eligible 62.6 years, p = 0.008) and a lower proportion had hypertension (23.9% vs 50.9%, p = 0.004), diabetes (6.4% vs 11.5%, p = 0.015), or a regular statin prescription (11.8% vs 26.7%, p = 0.001). Trial-ineligible populations had a higher hazard of MACE compared to trial-eligible in four RCTs and lower in ten (hazard ratio [HR] range across all RCTs 0.45 [95%CI 0.40-0.51] to 2.78 [95%CI 2.61-2.96]). Hazards of bleeding events in the trial-ineligible were lower than the trial-eligible in eight RCTs and higher in four (HR range across all RCTs 0.63 [95%CI, 0.59-0.66] to 1.69 [95%CI, 1.53-1.86]), and time-varying hazards of non-CVD death were consistently lower in four RCTs and higher in five (HR range across all RCTs and time points 0.29 [95%CI 0.24-0.36] to 11.42 [95%CI 9.91-13.17]). CONCLUSIONS: Compared with trial-ineligible populations within the same age and sex strata, RCTs recruited people of varying CVD risk but often excluded people at high risk of bleeding or non-CVD death, highlighting that many trials may overestimate the net benefit of aspirin for primary prevention.

Humans↗

PubMed2003

Inflammatory bowel disease activity assessment with biologic markers and 99mTc-WBC scintigraphy: are there different trends in ileitis versus colitis?

UNLABELLED: To evaluate whether scintigraphy with (99m)Tc-labeled white blood cells (WBC) can assess the intensity of bowel inflammation, a large dataset of laboratory values and clinical activity indices was correlated with (99m)Tc-WBC scintigraphy in children with Crohn's disease (CD), ulcerative colitis (UC), and miscellaneous colitis (MC). Also evaluated was whether stratification of children with CD as ileitis versus colitis results in different correlation coefficients for laboratory values versus (99m)Tc-WBC scintigraphy. METHODS: Over a 6-y period, 313 (99m)Tc-WBC studies were performed. A dataset of 2,714 laboratory values is available for analysis. RESULTS: There is a positive correlation between the erythrocyte sedimentation rate (ESR) and large bowel uptake of (99m)Tc-WBC (P < 0.05) and a negative trend with small bowel uptake of (99m)Tc-WBC in children with CD. Similarly, there is a correlation between WBC counts and scintigraphy in most segments of the large bowel and a negative correlation with the small bowel (R = -0.32, P = 0.01) in children with CD. There is a correlation between platelets and (99m)Tc-WBC in children with CD or UC. There is no correlation between the ESR and (99m)Tc-WBC in children with UC or MC. Many clinical activity indices correlate (P < 0.001) with (99m)Tc-WBC in children with CD, but none correlates in children with UC. Numerous laboratory values correlate with each other. There is a negative correlation between protein, albumin, hemoglobin, and hematocrit versus (99m)Tc-WBC scintigraphy in children with CD. In children with UC, there is a negative correlation between hemoglobin and hematocrit versus (99m)Tc-WBC. CONCLUSION: (99m)Tc-WBC scintigraphy, ESR, and WBC counts are good indicators of the inflammatory activity in CD if the inflammation is limited to the large bowel. There is a trend toward an inverse relationship when the inflammation is limited to the small bowel; thus, scintigraphy and the aforementioned markers may be of limited value. This report also demonstrates that (99m)Tc-WBC scintigraphy correlates with clinical activity indices in CD and with numerous biologic markers. In children with UC, scintigraphy with (99m)Tc-WBC and most laboratory markers are of limited value in assessing disease activity.

Adolescent↗

PubMed2001

Canadian Aboriginal communities and medical service patterns for the management of injured patients: a basis for surveillance.

Growing attention has been placed on injury as a major public health problem which has served to highlight the need for relevant injury data for preventive purposes at the community level. In the case of reserve-based Aboriginal communities in Canada, available injury data, from large datasets, often has little or no relevance at the community level. In addition, the availability of local data is complicated by unique health service and community infrastructures. As such, a prerequisite to establishing injury surveillance requires an understanding of Medical Service Patterns (MSPs) for injured patients intrinsic to a community's health service infrastructure. In determining patterns, cultural and environmental contexts are integral to methodological considerations as historically, Canada's Aboriginal population has been 'controlled' by others in the areas of health, education and social services. The objective of the study was to investigate MSPs in a Canadian Aboriginal community, specific to the management of injured patients, for the purpose of identifying data sites, sources, and collectors. The method relied on a four-step qualitative process designed explicitly for the study community, comprising: (1) semi-structured interviews with key informants; (2) a flow diagram process; (3) focus group discussions; and (4) a summary matrix diagram. This methodology was later replicated with three additional pilot communities. Three major MSPs were identified from nine original patterns generated through the initial data collection process. MSPs were found to be most directly impacted by severity of injury and the proximity of health service providers. Data collection practices were inconsistent, sporadic and poorly coordinated. Data was exclusive to respective data sources and off-reserve documentation was not reported back to the community. MSPs identified key data sites, sources, and collectors relevant to the study population. In conclusion, the four-step qualitative methodology employed in the study was found to be reliable and feasible in identifying community MSPs. Empirical findings confirm the need to investigate MSPs in communities considering surveillance activities, as intra-national differences may be considerable given social inequalities, geographic uniqueness and cultural factors. The use of sophisticated methodologies may detract rather than promote collaborative efforts.

Alberta↗

PubMed2004

Efficacy and safety of transdermal fentanyl and sustained-release oral morphine in patients with cancer and chronic non-cancer pain.

PURPOSE: To evaluate effectiveness and safety information of transdermal fentanyl (TDF) (Duragesic/Durogesic) and sustained-release oral morphine (SRM) in cancer pain (CP) and chronic non-cancer pain (NCP), a pooled analysis was conducted on datasets of published, open label, uncontrolled (no comparator group) and randomised controlled (with SRM as comparator) studies of TDF. PATIENTS AND METHODS: Eight trials with treatment durations of at least 28 days met the inclusion criteria. The effectiveness analysis assessed changes in average pain and pain 'right now' scores between baseline and Day 28. The safety analysis evaluated the incidence of adverse events (AEs) reported within the first 28 days of treatment with TDF or SRM. Subgroup analyses included pain type, gender, age, weight, and body mass index. RESULTS: Pooled efficacy data were available from 1220 patients; these showed that both TDF and SRM were effective in improving pain 'right now' scores (0-100 scale) from baseline to Day 28. The improvement was significantly more pronounced in the TDF treatment group (-26.7 +/- 31.3 for TDF, -18.7 +/- 30.9 for SRM, p = 0.002). This favourable effect of TDF was most apparent amongst patients with NCP. Data concerning AEs were available from over 2500 patients with CP (3 out of 10 patients) or chronic NCP (7 out of 10 patients). Significantly fewer patients in the TDF than in the SRM group reported any AE (72% vs. 87% respectively; p < 0.001), or an AE leading to the study drug being permanently discontinued (16% vs. 23% respectively; p < 0.001). Constipation and somnolence occurred considerably less frequently in the TDF than in the SRM treatment group. This difference was statistically significant in both the CP and NCP subgroups. CONCLUSION: This pooled data analysis provides expanded insight into the safety and effectiveness profile of transdermal fentanyl in patients with chronic pain. It shows significantly improved pain relief with transdermal fentanyl compared with sustained-release oral morphine, and supports current evidence of favourable tolerability of transdermal fentanyl, particularly with regard to reduced constipation and somnolence.

Administration, Cutaneous↗

PubMed1999

Binge status as a predictor of weight loss treatment outcome.

OBJECTIVE: A widely held clinical belief is that individuals with binge eating problems fare poorly in weight loss programs. The empirical evidence regarding the prognostic significance of binge eating, however, is mixed. The goals of this study were to examine psychological and behavioral characteristics associated with binge eating and the prognostic significance of binge eating for short- and long-term weight loss in a large sample of women treated for obesity. DESIGN: The dataset used in the current study was a combined sample of women (n = 444) who participated in one of three behavioral weight loss research studies. MATERIALS AND METHOD: Measures of dieting and weight history were obtained at baseline. Body weight, the Binge Eating Scale (BES), a measure of perceived barriers to weight loss, the Beck Depression Inventory, the Block Food Frequency Questionnaire, and the Paffenbarger Physical Activity Questionnaire were assessed at baseline, 6 months and 18 months. Regression analyses examined cross-sectional associations between the BES and the other variables at baseline, prospective associations between baseline BES and changes in weight and the psychological and behavioral variables over time, and temporal covariations between BES and the other variables over time. RESULTS: Cross-sectional analyses showed baseline binge eating status to be strongly associated with dieting history, weight cycling, depressive symptomatology and perceived barriers to weight loss. Women with binge eating problems were also more likely to drop out of treatment. Baseline binge status was not associated with 6-month weight loss, but was weakly predictive of less weight loss success at 18 months. Binge status at baseline did not predict changes in dietary intake, physical activity, perceived barriers to weight loss or depressive symptomatology at either 6 months or 18 months. In time-dependent covariance analyses, changes in BES scores were significantly associated with changes in body weight, independent of changes in dietary intake and physical activity. However, when depression scores are included in the analysis, the association between binge score and body weight was no longer statistically significant. CONCLUSION: These findings suggest that baseline binge status was a weak prognostic indicator of success in women who are moderately obese and are seeking treatment for weight loss. Although assessments of binge status covary with weight loss and regain, the relationship appears to be mediated by psychological dysphoria.

Adult↗

PubMed2005

Comparison of the minimally important difference for two health state utility measures: EQ-5D and SF-6D.

BACKGROUND: The SF-6D and EQ-5D are both preference-based measures of health. Empirical work is required to determine what the smallest change is in utility scores that can be regarded as important and whether this change in utility value is constant across measures and conditions. OBJECTIVES: To use distribution and anchor-based methods to determine and compare the minimally important difference (MID) for the SF-6D and EQ-5D for various datasets. METHODS: The SF-6D is scored on a 0.29-1.00 scale and the EQ-5D on a -0.59-1.00 scale, with a score of 1.00 on both, indicating 'full health'. Patients were followed for a period of time, then asked, using question 2 of the SF-36 as our anchor, if their general health is much better (5), somewhat better (4), stayed the same (3), somewhat worse (2) or much worse (1) compared to the last time they were assessed. We considered patients whose global rating score was 4 or 2 as having experienced some change equivalent to the MID. This paper describes and compares the MID and standardised response mean (SRM) for the SF-6D and EQ-5D from eight longitudinal studies in 11 patient groups that used both instruments. RESULTS: From the 11 reviewed studies, the MID for the SF-6D ranged from 0.011 to 0.097, mean 0.041. The corresponding SRMs ranged from 0.12 to 0.87, mean 0.39 and were mainly in the 'small to moderate' range using Cohen's criteria, supporting the MID results. The mean MID for the EQ-5D was 0.074 (range -0.011-0.140) and the SRMs ranged from -0.05 to 0.43, mean 0.24. The mean MID for the EQ-SD was almost double that of the mean MID for the SF-6D. CONCLUSIONS: There is evidence that the MID for these two utility measures are not equal and differ in absolute values. The EQ-5D scale has approximately twice the range of the SF-6D scale. Therefore, the estimates of the MID for each scale appear to be proportionally equivalent in the context of the range of utility scores for each scale. Further empirical work is required to see whether or not this holds true for other utility measures, patient groups and populations.

Attitude to Health↗

PubMed1991

Vegetable and fruit consumption and cancer risk.

The relationship between cancer risk and frequency of consumption of green vegetables and fruit has been analyzed using data from an integrated series of case-control studies conducted in northern Italy between 1983 and 1990. The overall dataset included the following histologically confirmed cancers: oral cavity and pharynx, 119; oesophagus, 294; stomach, 564; colon, 673; rectum, 406; liver, 258; gall-bladder, 41; pancreas, 303; larynx, 149; breast, 2,860; endometrium, 567; ovary, 742; prostate, 107; bladder, 365; kidney, 147; thyroid, 120; Hodgkin's disease, 72; non-Hodgkin lymphomas, 173; myelomas, 117; and a total of 6,147 controls admitted to hospital for acute non-neoplastic conditions, unrelated to long-term dietary modifications. Multivariate relative risks (RR) for subsequent tertiles of vegetable and fruit consumption were derived after allowance for age, sex, area of residence, education and smoking. For vegetables, there was a consistent pattern of protection for all epithelial cancers, with RRs in the upper tertile ranging from 0.2 for oesophagus, liver and larynx to 0.7 for breast. All the trends in risk were in the same direction and significant for all carcinomas except gall-bladder. In contrast, no protection was afforded by high vegetable consumption against non-epithelial lymphoid neoplasms. With reference to fruit, strong inverse relationships were observed for cancers of the upper digestive and respiratory tract, with RRs in the upper tertile between 0.2 and 0.3 for oral cavity and pharynx, oesophagus and larynx relative to the lowest tertile. The lower the location of the tumour in the digestive tract, the weaker appeared to be the protection afforded. Significant inverse relationships were observed for liver, pancreas, prostate and urinary sites, but not for rectum, breast and female genital cancers or thyroid. No relationship emerged for lymphomas and myelomas. Even in the absence of a clear biological interpretation, the consistency and strength of the patterns observed indicate that, in this population, frequent green vegetable intake is associated with a substantial reduction of risk for several common epithelial cancers, and that fruit intake has a favourable effect, especially on upper digestive cancers and, probably, also on urinary tract neoplasms.

Adult↗

PubMed2001

Prescription of methylphenidate to children and youth, 1990-1996.

BACKGROUND: There are concerns about the frequency and appropriateness of psychostimulant drug prescription to children. In order to identify unusual or unexpected patterns of use or prescribing, we reviewed prescription of methylphenidate (Ritalin) to children and adolescents aged 19 years or less in British Columbia between 1990 and 1996. METHODS: We obtained information about patients, physicians and prescriptions from British Columbia's Triplicate Prescription Program database for controlled drugs. Prescription data were available for the period Jan. 1, 1990, to Dec. 31, 1996. Linkage with the BC Linked Health Dataset provided additional demographic and health information. RESULTS: In 1990, 1715 children received at least 1 prescription for methylphenidate (1.9 per 1000 children). By 1996, the number had increased to 10,881 children (11.0 per 1000). Because some children were prescribed methylphenidate in more than 1 year, we also calculated the frequency with which the drug was prescribed to children who had never received it before. This rate increased from 1.0 per 1000 children in 1990 to 4.7 per 1000 in 1995; the rate fell in 1996 to 3.5 per 1000. The number of children receiving methylphenidate varied across health regions of the province, from 12.0 to 35.4 per 1000. Use also varied by socioeconomic status quintile: in the 2 lowest (least privileged) quintiles, 21.6 per 1000 children received methylphenidate, compared with 18.4 per 1000 in the 3 highest quintiles (relative risk 1.2, 95% confidence interval 1.1-1.2). Pediatricians and psychiatrists wrote 23% and 21% of all prescriptions respectively. General practitioners accounted for 56% of all prescriptions and 41% of initial methylphenidate prescriptions. A claim for prior specialist consultation was found in 30% of such cases. Many of the children who received more than 10 prescriptions had seen 4 or more physicians. The average daily dosage prescribed differed little among general practitioners, pediatricians and psychiatrists, unlike the mean interval between successive prescriptions: 89.9 (standard deviation [SD] 68.2), 99.8 (SD 64.1) and 75.9 (SD 70.2) days respectively. Persistence with therapy was more likely when a psychiatrist provided the initial prescription, or with involvement of more than one specialty. INTERPRETATION: Many trends and practices in the prescription of methylphenidate to children in British Columbia are consistent with other settings and accepted standards. Some aspects warrant closer investigation, including regional and socio-economic discrepancies in the distribution of patients, the relative involvement of primary and specialist care providers, continuity of care issues and time intervals between prescriptions.

Adolescent↗

PubMed2004

The external validity of results derived from ecstasy users recruited using purposive sampling strategies.

This study sought to compare the patterns and correlates of 'recent' and 'regular' ecstasy use estimated on the basis of two datasets generated in 2001 in New South Wales, Australia, from a probability and a non-probability sample. The first was the National Drug Strategy Household Survey (NDSHS), a multistage probability sample of the general population; and the second was the Illicit Drug Reporting System (IDRS) Party Drugs Module, for which regular ecstasy users were recruited using purposive sampling strategies. NDSHS recent ecstasy users (any use in the preceding 12 months) were compared on a range of demographic and drug use variables to NDSHS regular ecstasy users (at least monthly use in the preceding 12 months) and purposively sampled regular ecstasy users (at least monthly use in the preceding 6 months). The demographic characteristics of the three samples were consistent. Among all three, the mean age was approximately 25 years, and a majority (60%) of subjects were male, relatively well-educated, and currently employed or studying. Patterns of ecstasy use were similar among the three samples, although compared to recent users, regular users were likely to report more frequent use of ecstasy. All samples were characterised by extensive polydrug use, although the two samples of regular ecstasy users reported higher rates of other illicit drug use than the sample of recent users. The similarities between the demographic and drug use characteristics of the samples are striking, and suggest that, at least in NSW, purposive sampling that seeks to draw from a wide cross-section of users and to sample a relatively large number of individuals, can give rise to samples of ecstasy users that may be considered sufficiently representative to reasonably warrant the drawing of inferences relating to the entire population. These findings may partially offset concerns that purposive samples of ecstasy users are likely to remain a primary source of ecstasy-related information.

Adolescent↗

PubMed2006

Breast cancer prognosis by combinatorial analysis of gene expression data.

INTRODUCTION: The potential of applying data analysis tools to microarray data for diagnosis and prognosis is illustrated on the recent breast cancer dataset of van 't Veer and coworkers. We re-examine that dataset using the novel technique of logical analysis of data (LAD), with the double objective of discovering patterns characteristic for cases with good or poor outcome, using them for accurate and justifiable predictions; and deriving novel information about the role of genes, the existence of special classes of cases, and other factors. METHOD: Data were analyzed using the combinatorics and optimization-based method of LAD, recently shown to provide highly accurate diagnostic and prognostic systems in cardiology, cancer proteomics, hematology, pulmonology, and other disciplines. RESULTS: LAD identified a subset of 17 of the 25,000 genes, capable of fully distinguishing between patients with poor, respectively good prognoses. An extensive list of 'patterns' or 'combinatorial biomarkers' (that is, combinations of genes and limitations on their expression levels) was generated, and 40 patterns were used to create a prognostic system, shown to have 100% and 92.9% weighted accuracy on the training and test sets, respectively. The prognostic system uses fewer genes than other methods, and has similar or better accuracy than those reported in other studies. Out of the 17 genes identified by LAD, three (respectively, five) were shown to play a significant role in determining poor (respectively, good) prognosis. Two new classes of patients (described by similar sets of covering patterns, gene expression ranges, and clinical features) were discovered. As a by-product of the study, it is shown that the training and the test sets of van 't Veer have differing characteristics. CONCLUSION: The study shows that LAD provides an accurate and fully explanatory prognostic system for breast cancer using genomic data (that is, a system that, in addition to predicting good or poor prognosis, provides an individualized explanation of the reasons for that prognosis for each patient). Moreover, the LAD model provides valuable insights into the roles of individual and combinatorial biomarkers, allows the discovery of new classes of patients, and generates a vast library of biomedical research hypotheses.

Breast Neoplasms↗

PubMed2005

Risk of cardiac death after adjuvant radiotherapy for breast cancer.

BACKGROUND: Women with breast cancer who are treated with adjuvant radiation have a decreased risk of local recurrence but an increased risk of mortality from ischemic heart disease. Patients with left-sided breast tumors receive a higher dose of radiation to the heart than patients with right-sided tumors. Because radiation techniques have improved over time, we investigated whether the risk of death from ischemic heart disease after adjuvant breast radiotherapy decreased over time. METHODS: We used the 12-registry 1973-2000 dataset from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. Women (n = 27,283) treated with adjuvant radiation for breast cancer diagnosed in 1973-1989 were included in the study. Ischemic heart disease mortality was calculated at 15 years and compared for women diagnosed during 1973-1979, 1980-1984, and 1985-1989. Cox proportional hazards models were used to calculate the hazard of death from ischemic heart disease for women diagnosed 1973-1988 and censored at 12 years. All statistical tests were two-sided. RESULTS: There were no differences in age, race/ethnicity, disease stage, or follow-up time between the 13 998 women with left-sided and 13 285 with right-sided cancer. For women diagnosed in 1973-1979, there was a statistically significant difference in 15-year mortality from ischemic heart disease between patients with left-sided (13.1%, 95% confidence interval [CI] = 11.6 to 14.6) and those with right-sided (10.2%, 95% CI = 8.9 to 11.5) breast cancer (P = .02); no such difference was found for women diagnosed in 1980-1984 (9.4%, [95% CI = 8.1 to 10.6] versus 8.7% [95% CI = 7.4 to 10.0], respectively, P = .64) or 1985-1989 (5.8% [95% CI = 4.8 to 6.8] versus 5.2% [95% CI = 4.4 to 5.9], respectively, P = .98). In the Cox model, the hazard ratio [HR] for ischemic heart disease mortality for women with left-sided versus women with right-sided disease was 1.50 (95% CI = 1.19 to 1.87) in 1979. With each succeeding year after 1979, the hazard of death from ischemic heart disease for women with left-sided versus those with right-sided disease declined by 6% (HR = 0.94, 95% CI = 0.91 to 0.98). CONCLUSIONS: Risk of death from ischemic heart disease associated with radiation for breast cancer has substantially decreased over time.

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PubMed2003

Vaccines for preventing pneumococcal infection in adults.

BACKGROUND: Diseases caused by Streptococcus pneumoniae (S. pneumoniae) continue to cause substantial morbidity and mortality throughout the world. Polysaccharide pneumococcal vaccines have been developed for over 50 years and may have the potential to prevent disease and death. OBJECTIVES: To assess the effectiveness of polysaccharide pneumococcal vaccination in preventing disease or death in adults. SEARCH STRATEGY: Trials were identified by electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) issue 2, 2003 (which includes the Cochrane ARI Group's specialised register); MEDLINE (January 1966 to June 2003); and EMBASE (1974 to June 2003). We searched existing literature. The bibliographies of all newly revealed studies were read in order to identify further studies. The vaccine manufacturers, the lead authors of newly identified studies not included in existing meta-analyses were contacted. SELECTION CRITERIA: A) Prospective, randomised or quasi-randomised studies comparing pneumococcal vaccines with placebo, control vaccines or no intervention.B) Case-control studies (including indirect cohort studies) assessing pneumococcal vaccine effectiveness against invasive pneumococcal disease. Cohort studies are excluded. DATA COLLECTION AND ANALYSIS: A) Randomised studies. Trial quality assessment was conducted by two reviewers (JH and DT). Data extraction was done by three reviewers (JH, DT, KD). There were many instances of unclear or incomplete data in the trial reports, and the final dataset was arrived at after much deliberation and discussion, including comparison with the data used in two previous reviews of this question. Due to the age of the trials (dating back to 1954 in one case) it was not generally possible to obtain clarification from the authors, though a partial clarification was achieved in one case.B) Non-randomised studies. Study quality was assessed by two reviewers (RA and KD). MAIN RESULTS: The combined results from the randomised studies fail to show that the polysaccharide pneumococcal vaccine is effective in preventing either pneumonia (outcome 6: odds ratio = 0.77, confidence interval 0.58, 1.02, number = 14) or death (outcome 8: odds ratio 0.90, confidence interval 0.76, 1.07, number = 11). Despite encouraging data from some very early trials, pooling trials published from 1977 on suggests there is no effect (outcome 6; odds ratio = 0.96, confidence interval 0.80, 1.15, number = 12; outcome 9: odds ratio = 0.98, confidence interval 0.88, 1.09, number = 10). The available data cannot distinguish whether this heterogeneity in results is due to improvements in trial methodology and reporting, to differences in trial setting or to real loss of efficacy over time. This is because the early, poorly reported trials were conducted in high-risk healthy populations where the expected benefit is greatest. The case-control studies show significant efficacy in preventing invasive pneumococcal disease: OR 0.47 (CI 0.37, 0.59) corresponding to an efficacy of 53%. REVIEWER'S CONCLUSIONS: While polysaccharide pneumococcal vaccines do not appear to reduce the incidence of pneumonia or death in adults with or without chronic illness, or in the elderly (55 years and above), the evidence from non-randomised studies suggests that the vaccines are effective in the reducing the incidence of the more specific outcome, invasive pneumococcal disease, among adults and the immunocompetent elderly (55 years and above). Surveillance data suggest that infection rates vary widely between and also within countries, but a typical figure in developed countries is 0.01%, or 10 per 100,000 per year. Efficacy of 50% then corresponds to a number-needed-to-treat (NNT) of 20,000 vaccinations per infection avoided, and perhaps 50,000 per death avoided.

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PubMed2004

Mississippi's physician labor force: current status and future challenges.

The literature review indicates that changes in Medicaid/Medicare reimbursement, large numbers of uninsured patients, the legal climate, and largely rural and chronically ill populations create a challenging environment for physicians practicing in Mississippi. As a largely rural state, many Mississippians find medical care to be physically distant, with most care being concentrated in a couple areas of the state. Given these factors, the legal climate in Mississippi and the top relocation decision factors, Mississippi will be further challenged in recruiting and retaining the numbers of general practitioners and specialists necessary to provide care to the state's population. The challenges that physicians are facing have led to challenges for health policy makers, in that physicians are difficult to recruit to Mississippi and, once here, difficult to retain as practitioners throughout their career. Four datasets were used in conjunction to analyze the demographic characteristics of Mississippi's physicians, including the age structure disaggregated by several other variables. Ultimately, the results were extended to impacts of recruitment, relocations, and retirement decisions of physicians who participated in the MSMDS. Briefly, demographic results indicate that Mississippi has a largely white physician population serving a nearly 40% minority population in Mississippi. The under representation of women within the medical profession in Mississippi means that women in the state might find it unusually challenging to find a female physician, particularly in rural areas where access to physicians is more limited in the first place. Mississippi has a high concentration of African-American patients with a low African-American physician presence. The proportion of physicians who are female is on the rise nationwide and within Mississippi, largely due to increasing enrollments of women in medical schools. Though variations exist within the groups of physicians identified as generalists, Mississippi is only slightly more likely than the nation to have specialists, rather than generalists (see Table Seven). Age structure analysis indicates that Delta physicians are older than physicians elsewhere in the state, that urban physicians are younger than rural physicians, and that our physician labor force is more highly concentrated between the ages of 35 and 54 than in the nation as a whole. Analyses concerning the future of the physician labor force indicate that a near majority of Mississippi's practicing physicians received their MD degree at UMC, but younger physicians are more likely to have been educated out-of-state than older physicians. Those who received their degrees elsewhere and chose to practice in Mississippi are more likely to be specialists (60%) than generalists (40%). Those physicians practicing in the state who were educated in-state are nearly equally as likely to be generalists (47%) as they are to be specialists (53%). Additionally, those approaching retirement are more likely to be generalists, yet the state is recruiting more generalists from recent medical school classes than in the past. Variations in intentions to recruit, relocate, and retire exist. However, most of the substantively important variation is across age groups and time in practice. There is little relevance of specialty or location within the state when examining variation in recruitment, relocation or retirement plans. Given the findings, policy research recommendations focus on improving the retention of UMC's graduates for practice in the state, improving retention of active physicians, increasing the recruitment of physicians from out of state, and easing difficulties associated with working part-time as a step toward retirement. With these changes in policy, it is possible that Mississippi can thwart a physician workforce shortage; however, without changes, with more physicians relocating, retiring early, or opting out of practicing in the state, the extant physician shortage will become more severe. Furthermore, without the data collection efforts mentioned here, there will be no means to assess whether policy changes are actually impacting the physician labor force.

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