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S R Cole

Publications and source records attributed to S R Cole.

At least 19 recordsLinked to original sources

Glomerular filtration rate via plasma iohexol disappearance: pilot study for chronic kidney disease in children.

To guide the design of a nation-wide cohort study of chronic kidney disease in children, we determined how iohexol plasma disappearance curves could be used in children to measure glomerular filtration rate (GFR). Iohexol (5 ml) was administered intravenously and blood samples were obtained at 10, 20, 30, 60, 120, 240, 300, and 360 min after injection (N=29) and assayed by high performance liquid chromatography. Four urines were also collected following the injection. Intra-assay coefficient of variation (CV) in serum was 1.3% at 100 mg/l, 2.6% at 15 mg/l, and 3.4% for duplicate unknowns. GFR(9) was computed from iohexol dose and area under the nine-point blood disappearance curve, using double exponential modeling. Only 2.8% of 254 data points deviated by >3 CV from the curves. GFR(4) calculated from 10, 30, 120, and 300 min points correlated well with GFR(9) (r=0.999) and showed no bias (means+/-s.d. of GFR(9) and GFR(4)=59.3+/-36.3 and 59.4+/-36.0 ml/min per 1.73 m(2)). Relationship of GFR(9) and one-compartment GFR followed quadratic equation as previously reported by Brochner-Mortensen, allowing GFR to be calculated from 120 and 300 min points. This GFR(2) correlated well with GFR(9) (r=0.986). Estimated GFR from Schwartz height/creatinine formula correlated with GFR(9)(r=0.934) but overestimated GFR by 12.2 ml/min per 1.73 m(2). Urine iohexol clearance was poorly correlated (r=0.770) with GFR(9) owing to variability in urine collections (median CV=24%). GFR can be measured accurately using four-point iohexol plasma disappearance (in most cases, two points suffice); estimated GFR and urinary clearances are less useful.

Adolescent↗

Screening for colorectal cancer by faecal occult blood test: why people choose to refuse.

To better understand the personal barriers that limit participation in faecal occult blood test (FOBT) screening for colorectal cancer, non-participants from a recent screening initiative were sent detailed questionnaires, defining their reasons for not participating, as well as how to make screening more attractive. The important barrier was procrastination. The type of FOBT kit offered influenced the reasons for not participating. Convenient FOBT and greater general practitioner involvement may be important for optimizing community acceptance of FOBT-based screening.

Aged↗

Interval faecal occult blood testing in a colonoscopy based screening programme detects additional pathology.

BACKGROUND: Colonoscopic based surveillance is recommended for patients at increased risk of colorectal cancer. The appropriate interval between surveillance colonoscopies remains in debate, as is the "miss rate" for colorectal cancer within such screening programmes. AIMS: The main aim of this study was to determine whether a one-off interval faecal occult blood test (FOBT) facilitates the detection of significant neoplasia within a colonoscopic based surveillance programme. Secondary aims were to determine if invitees were interested in participating in interval screening, and to determine whether interval lesions were missed or whether they developed rapidly since the previous colonoscopy PATIENTS: Patients enrolled in a colonoscopic based screening programme due to a personal history of colorectal neoplasia or a significant family history. METHODS: Patients within the screening programme were invited to perform an immunochemical FOBT (Inform). A positive result was followed by colonoscopy; significant neoplasia was defined as colorectal cancer, adenomas either > or =10 mm or with a villous component, high grade dysplasia, or multiplicity (>/=3 adenomas). Participation rates were determined for age, sex, and socioeconomic subgroups. Colonoscopy recall databases were examined to determine the interval between previous colonoscopy and FOBT offer, and correlations between lesion characteristics and interval time were determined. RESULTS: A total of 785 of 1641 patients invited (47.8%) completed an Inform kit. A positive result was recorded for 57 (7.3%). Fifty two of the 57 test positive patients completed colonoscopy; 14 (1.8% of those completing the FOBT) had a significant neoplastic lesion. These consisted of six colorectal cancers and eight significant adenomas. CONCLUSIONS: A one off immunochemical faecal occult blood test within a colonoscopy based surveillance programme had a participation rate of nearly 50% and appeared to detect additional pathology, especially in patients with a past history of colonic neoplasia.

Adult↗

The use of Alu-PCR to distinguish between typical pulmonary carcinoids versus classic midgut carcinoids.

Although histologically 'typical' pulmonary and 'classic' midgut carcinoids are similar, the small intestine tumors are more aggressive than their pulmonary counterpart. We believe that in contrast to pulmonary carcinoids arising from Kulchitsky cells, 'classical' midgut carcinoids develop from crypt stem cells that differentiate into endocrine ('classical') or exocrine-endocrine ('non-classical' adenocarcinoid) tumors. The different progenitor cells may determine different malignant potentials between these types of carcinoids. To identify genetic differences between 'classical' midgut and typical pulmonary carcinoids using an Alu-PCR genomic profiling method, we reviewed 54 cases of carcinoid tumors that were surgically removed at Hartford Hospital from 1996 through 2001. Histologically these cases were selected into three groups: i) foregut or pulmonary carcinoids, ii) 'classic' midgut carcinoids of small intestine and iii) multiple typical pulmonary carcinoids. Genomic-profiling of DNA from these cases was performed using an Alu-PCR method. Metastases were observed in 18/20 'classical' intestinal carcinoid tumors, 3/30 pulmonary carcinoids, and 0/4 multiple pulmonary carcinoids. These results confirm that pulmonary carcinoids behave in a more benign fashion than intestinal carcinoid tumors. Using Alu-PCR to profile tumor cell genomic DNA, we showed that 68% of small intestine carcinoids and 58% of pulmonary carcinoids had allelic banding patterns suggestive of either amplification or deletion of gene sequences. Alu-PCR demonstrated loss or gain of genetic sequences that were unique for each examined group. These findings strongly suggest that pulmonary carcinoids differ from their intestinal counterparts.

Alu Elements↗

A randomised trial of the impact of new faecal haemoglobin test technologies on population participation in screening for colorectal cancer.

OBJECTIVES: To investigate the effect on participation in colorectal cancer screening of testing for blood products in faeces using technologies that remove dietary restrictions (i.e. immunochemical tests) and simplify faecal sampling (i.e. tests that use brush sampling). METHODS SETTING: Urban residents (n=1818) of Adelaide, Australia, aged between 50 and 69 years, randomly selected from the electoral roll. DESIGN: Three randomised cohorts of 606 invitees were offered a screening test by mail in 2001. The Hemoccult SENSA and FlexSure OBT cohorts were instructed to sample three stools using a spatula while the InSureTM cohort sampled two stools using a brush. The Hemoccult SENSA cohort was asked to restrict certain (high-peroxidase) foods and drugs. MAIN OUTCOME MEASURES: Participation (i.e. return of completed sample kits within 12 weeks) and generalised linear modelling (GLM) of relationships between participation, test technologies and demographic variables. RESULTS: Participation was 23.4%, 30.5% and 39.6% for the Hemoccult, FlexSure and InSure cohorts, respectively (chi(2)=37.1, p<0.00001). GLM demonstrated that participation was increased by 28% by removal of restrictions (p=0.01) and by 30% by simplification of sampling (p=0.001); both together increased participation by 66% (p<0.001). The differences in participation between tests occurred in the first three weeks. Socio-economic status, gender or age did not significantly influence technology-based improvements in participation. CONCLUSIONS: The brush-sampling faecal immunochemical test for haemoglobin (InSure) achieves the best participation rates by simplifying sampling and removing the need for restrictions of diet and drugs. Because participation in screening is vital to detection, this new technology should contribute to better detection of neoplasia at the population level.

Aged↗

Prescreening evaluation of a brush-based faecal immunochemical test for haemoglobin.

OBJECTIVES: To undertake a prescreening evaluation of a new brush-based faecal immunochemical test for haemoglobin, relative to a traditional spatula-sampling immunochemical test. METHODS SETTING: Patients aged between 24 and 90 years, scheduled to undergo diagnostic colonoscopy in two major urban hospitals, for a range of clinical indications. DESIGN: Patients sampled three stools using a spatula for the reference FlexSure OBT test and two stools using a brush for the InSure test; order of sampling was randomised. Faecal haemoglobin was quantified by a modified InSure in a subset of patients to determine whether brush-sampling allowed discrimination between groups. MAIN OUTCOME MEASURES: Sensitivity for cancer or adenoma; false-positive rate in normals. Faecal haemoglobin levels. Preference for sampling method. RESULTS: InSure and FlexSure OBT did not differ in their sensitivities for cancer (27/36, 75% vs 29/36, 80.5%, respectively), adenomas >or= 10 mm (12/29, 41.4% vs 13/29, 44.8%) or adenomas <10 mm (each 8/56, 14.3%). Likewise, false-positive rates in normals were similar: 4/179 (2.2%) and 5/179 (2.8%) respectively (specificities of 97.8% and 97.2%, respectively). Levels of faecal haemoglobin were highest in those with cancers; those with adenomas had intermediate levels which were also significantly higher than those in normals. The brush sampling method was preferred by 38/46 (82.6%), while 4/46 (8.7%) preferred the spatula (p<0.00001). CONCLUSIONS: InSure is as sensitive and specific as FlexSure OBT for faecal haemoglobin. The novel stool-sampling method of InSure allows discrimination between normals and classes of neoplasia, and is highly preferred. The brush-sampling faecal immunochemical test InSure should now be evaluated in a screening population.

Adenoma↗

Participation in screening for colorectal cancer based on a faecal occult blood test is improved by endorsement by the primary care practitioner.

OBJECTIVES: To investigate the influence of general practitioner (GP) endorsement on participation in screening for colorectal cancer based on a faecal occult blood test (FOBT). SETTING: South Australian residents (n=2400), in 1999, aged >50 years. METHODS: Random selection of three groups (GP1, GP2, GP3) from two general practices and of one group (ER) from the federal electoral roll; n=600 per group. Without previous communication or publicity, subjects were posted an offer of screening by immunochemical FOBT. The GP1 and ER groups were invited without indication that their GP was involved; GP2 received an invitation indicating support from the practice; and GP3 received an invitation on practice letterhead and signed by a practice partner. A reminder was posted at 6 weeks. Participation was defined as return of correctly completed FOBT sample cards within 12 weeks. RESULTS: Participation rates were: GP1 192/600 (32.0%), GP2 228/600 (38.0%), and GP3 244/600 (40.7%); chi(2)=10.2, p=0.006. Both GP2 and GP3 differed significantly from GP1 (odds ratio (OR) 0.77, 95% confidence interval (95% CI) 0.60 to 0.98 and relative risk (RR)=0.69, 95% CI 0.54 to 0.87 respectively). ER (193/600 (32.2%)) and GP1 were not significantly different. Age but not sex was significantly associated with participation. Overall test positivity rate was 4.6%; five malignancies were found in the 918 who performed FOBT. CONCLUSIONS: Association of a GP of recent contact with a screening offer in the form of a personalised letter of invitation achieves better participation than does the same letter from a centralised screening unit that does not mention the GP. Thus, GP enhanced participation is achievable without their actual involvement. Additional strategies are needed to further improve participation.

Age Factors↗

Effect of dietary restriction on participation in faecal occult blood test screening for colorectal cancer.

OBJECTIVES: To determine if participation in colorectal cancer screening using faecal occult blood testing (FOBT) is affected by a restrictive diet and if it is associated with certain demographic variables. PARTICIPANTS AND SETTING: 1,203 residents of South Australia aged 50-69 years, with no "currently active bowel disease", randomly selected from a database of people willing to be contacted about unspecified health issues. DESIGN: Randomised controlled trial: participants were offered screening by immunochemical FOBT by mail in 1998. Half were randomly allocated to a group instructed to follow a low-peroxidase diet, as required for guaiac FOBT, while the other group was not so restricted. MAIN OUTCOME MEASURES: Effect of diet restriction on participation (return of correctly completed FOBT sample cards within 15 weeks); time taken to return cards; relationships between participation and demographic variables. RESULTS: Participation rates were 65.9% (no-diet group) and 53.3% (diet group) (difference, 12.6%; 95% CI, 7.1%-18.1%). In the first week, rates of return as a proportion of all tests returned were 13.1% (no-diet) and 1.6% (diet) (difference, 11.5%; 95% CI, 8.6%-14.4%), increasing to 54.3% and 44.5%, respectively, after five weeks (difference, 9.8%; 95% CI, 4.2%-15.4%). Participation was significantly associated with older age (odds ratio, 1.40; 95% CI, 1.10-1.78), but not sex, Index of Social Disadvantage or rural versus urban address. CONCLUSIONS: Dietary restrictions create a barrier to FOBT-based screening for colorectal cancer. The use of immunochemical rather than guaiac FOBT removes this barrier.

Aged↗

Isolation of the components of a complex mixture by means of column switching for their enhanced detection by mass spectrometry.

Mass spectral characterization of low-level impurities in drug substances and formulations may be challenging when using a validated HPLC method developed for optimal chromatographic performance. In many cases, either the mobile phase contains non-volatile additives that are deleterious to the operation of the mass spectrometer, or some of the related substances fail to ionize effectively under electrospray ionization or atmospheric pressure chemical ionization conditions. This paper describes a way to capture these low-level compounds from an analytical HPLC column using a small trapping column. Mixture components are retained on the trapping column by means of reducing the solvent strength of the eluent. Subsequent elution of trapped compounds using mobile phases more amenable to mass spectral analysis yields improved detection and characterization of low-level compounds of interest. Possible applications of peak trapping and elution include: (1) analysis of compounds separated using a mobile phase containing high concentrations of non-volatile additives, (2) analysis of organic acids separated using a low-pH mobile phase (containing trifluoroacetic acid), and (3) improving the detection limit of a low-level compound of interest through multiple collections. The peak trapping apparatus and optimization experiments are described.

Chromatography, High Pressure Liquid↗

Analysis of complex survey data using SAS.

Commonly used statistical methods and software packages typically assume that observations are independent and identically distributed and fail to account for complex sampling designs when present. I suggest an approach to analyzing complex survey data in SAS, using weighted generalized estimating equations. Limited Monte Carlo simulations support the method. An example demonstrates application of the method and compares results to those from software commonly used in the analysis of complex survey data.

Aged↗

Recall bias in a prospective cohort study of acute time-varying exposures: example from the herpetic eye disease study.

Recall bias is possible in a prospective cohort study when exposure status is transient and must be periodically recalled, and ascertainment occurs after symptom onset. We know of no published demonstration of such bias at play in a prospective cohort study. In a substudy of a randomized clinical trial, 308 participants were prospectively followed to investigate potential acute triggers of ocular herpes simplex virus (HSV) recurrences. Participants reported on the presence of systemic infection or high psychological stress (exposures) on a home log that was completed weekly for up to 15 months and mailed to the study's coordinating centers. By protocol, exposure reporting was to occur on the last day of the week (Sunday) so that a prospective 1-week lag period between exposure and outcome in the following week could be assessed. The study outcome was development of a recurrence of ocular HSV disease documented by clinical examination. Using 35 weekly reports of exposure properly completed before the week of an outcome, there was no evidence of higher risk of HSV recurrence associated with systemic infection (rate ratio = 0.62, 95% confidence interval [CI]: 0.19-2.02) or high psychological stress rate (ratio = 0.0, 95% CI: 0.0-undefined). In contrast, when the analysis was based on 26 weekly reports of exposure improperly completed on or after the date of outcome, the risk of recurrence associated with systemic infection was estimated to be 4-fold (rate ratio = 4.07, 95% CI: 1.84-8.98), and there was a suggestion of a 2-fold risk associated with high psychological stress (rate ratio = 2.02, 95% CI: 0.69-5.91). Without real-time monitoring of exposure reporting, preservation of the temporal exposure-disease relationship-an implicit assumption of the prospective cohort study design-may be particularly tenuous when transient exposures are investigated longitudinally.

Bias↗

The Amblyopia Treatment Index.

OBJECTIVE: To develop a questionnaire to assess the acceptability of amblyopia treatment and its effect on the child and family. METHODS: A 20-item parental survey was developed and pilot tested on 64 subjects, aged 3 to 6 years, participating in the Amblyopia Treatment Study, a randomized trial comparing patching and atropine as treatments for moderate amblyopia. The survey was administered after 4 weeks of treatment. A descriptive item analysis and an internal consistency reliability analysis were performed. RESULTS: Nineteen of the 20 items demonstrated adequate variability as evidenced by the frequency distributions for item responses. Only 4 (<1%) of 1280 possible item responses were missing, one each by 4 different respondents. Factor analysis identified 3 treatment-related factors--"adverse effects," "compliance," and "social stigma"--among 11 of the 20 items. The internal-consistency reliability alpha for the 5-item adverse effects subscale was 0.82, the 4-item compliance subscale alpha was 0.81, and the 2-item social stigma subscale alpha was 0.84. CONCLUSIONS: The Amblyopia Treatment Index appears to be a useful instrument for assessing the impact of amblyopia treatment in 3- to 6-year-old children.

Amblyopia↗

Intake of vegetables rich in carotenoids and risk of coronary heart disease in men: The Physicians' Health Study.

BACKGROUND: Previous studies of diet and coronary heart disease (CHD) have focused on intake of nutrients rather than whole foods. Because of the findings that dietary fibre, folate and antioxidants may be protective for CHD, increased intake of vegetables has been recommended. However, due to the chemical and physical complexity of vegetables, the effects of individual nutrients may differ if eaten as whole foods. Moreover, little is known about the direct association between vegetable intake and risk of CHD. METHODS: We prospectively evaluated the relation between vegetable intake and CHD risk in the Physicians' Health Study, a randomized trial of aspirin and beta-carotene among 22 071 US male physicians aged 40-84 years in 1982. In this analysis, we included 15 220 men without heart disease, stroke or cancer at baseline who provided information on their vegetable intake at baseline, and in the 2nd, 4th and 6th years of follow-up using a simple semiquantitative food frequency questionnaire including eight vegetables. We confirmed 1148 incident cases of CHD (387 incident cases of myocardial infarction and 761 incident cases of coronary artery bypass grafting or percutaneous transluminal coronary angioplasty) during 12 years of follow-up. RESULTS: After adjusting for age, randomized treatment, body mass index (BMI), smoking, alcohol intake, physical activity, history of diabetes, history of hypertension, history of high cholesterol, and use of multivitamins, men who consumed at least 2.5 servings/day of vegetables had a relative risk (RR) of 0.77 (95% CI : 0.60-0.98) for CHD, compared with men in the lowest category (<1 serving/day). Adjusting for the same covariates in an analysis of the overall trend that considered intake of vegetables as a continuous variable, we found a RR of 0.83 (95% CI : 0.71-0.98) for risk of CHD for each additional serving/day of vegetables. The inverse relation between vegetable intake and CHD risk was more evident among men with a BMI > or =25 (RR = 0.71, 95% CI : 0.51-0.99) or current smokers (RR = 0.40, 95% CI : 0.18-0.86) comparing highest to the lowest categories of intake. CONCLUSIONS: Our results suggest an inverse association between vegetable intake and risk of CHD. These prospective data support current dietary guidelines to increase vegetable intake for the prevention of CHD.

Adult↗

Time urgency and risk of non-fatal myocardial infarction.

BACKGROUND: Inconsistencies in the literature linking Type A behaviour pattern (TAB) to coronary heart disease (CHD) may be due to differences in the effects of various components of TAB, namely aggressiveness, hostility, ambitiousness, competitive drive, and a chronic sense of time urgency. METHODS: We investigated the association between sense of time urgency/impatience and non-fatal myocardial infarction (MI) in a study of 340 cases and an equal number of age-, sex-, and community-matched controls. RESULTS: A dose-response relation was apparent among subjects who rated themselves higher on the four-item time urgency/impatience scale (P-value for trend <0.001), with a matched odds ratio (OR) for non-fatal MI of 4.45 (95% CI : 2.20-8.99) comparing those with the highest rating to those with the lowest. After further adjustment for family history of premature MI, physical activity, body mass index, occupation, cigarette smoking, total caloric intake, per cent calories from saturated fat, alcohol intake, lipid levels, treated hypertension and diabetes, the dose-response relation remained (P-value for trend = 0.015) and the adjusted OR for MI was 3.99 (95% CI : 1.32-12.0) comparing those with the highest rating to those with the lowest. CONCLUSION: In these data, a sense of time urgency/impatience was associated with a dose-response increase in risk of non-fatal MI, independent of other risk factors. Prospective cohort studies of time urgency/impatience and incident CHD events are needed to confirm or refute these observations from a case-control study.

Adult↗

Regression models for unconstrained, partially or fully constrained continuation odds ratios.

Epidemiologists frequently encounter studies with ordered responses. Standard ordered response logit models, such as the continuation ratio model, constrain exposure to have a homogeneous effect across thresholds of the ordered response. We demonstrate a method for fitting regression models for unconstrained, partially or fully constrained continuation odds ratios using a 'person-threshold' data set. For each subject, we create a separate record for each response threshold the subject is 'at risk' of passing and then apply standard binary logistic regression to estimate the continuation-ratio model. An example demonstrates the unconstrained, partially and fully constrained continuation-ratio model, while a small simulation study examines some properties of the proposed 'person-threshold' approach. Finally, we present a brief discussion of statistical software to implement the method.

Epidemiologic Methods↗

Interaction between HLA-DR2 and abnormal brain MRI in optic neuritis and early MS. Optic Neuritis Study Group.

The association of the human leukocyte antigen (HLA)-DR2 allele with brain MRI signal abnormalities and with the development of MS was assessed in 178 patients enrolled in the Optic Neuritis Treatment Trial. HLA haplotype DR2 was present in 85 (48%) of the 178 patients. Its presence was associated with increased odds of probable or definite MS at 5 years (odds ratio, 1.92; 95% confidence interval, 1.01 to 3.67; p = 0.04). The association was most apparent among patients with signal abnormalities on baseline brain MRI.

Administration, Oral↗

Test of item-response bias in the CES-D scale. experience from the New Haven EPESE study.

We present results of item-response bias analyses of the exogenous variables age, gender, and race for all items from the Center for Epidemiologic Studies Depression (CES-D) scale using data (N = 2340) from the New Haven component of the Established Populations for Epidemiologic Studies of the Elderly (EPESE). The proportional odds of blacks responding higher on the CES-D items "people are unfriendly" and "people dislike me" were 2.29 (95% confidence interval: 1.74, 3.02) and 2.96 (95% confidence interval: 2.15, 4.07) times that of whites matched on overall depressive symptoms, respectively. In addition, the proportional odds of women responding higher on the CES-D item "crying spells" were 2.14 (95% confidence interval: 1.60, 2.82) times that of men matched on overall depressive symptoms. Our data indicate the CES-D would have greater validity among this diverse group of older men and women after removal of the crying item and two interpersonal items.

Black or African American↗

Fruit and vegetable intake and risk of cardiovascular disease: the Women's Health Study.

BACKGROUND: Prospective data relating fruit and vegetable intake to cardiovascular disease (CVD) risk are sparse, particularly for women. OBJECTIVE: In a large, prospective cohort of women, we examined the hypothesis that higher fruit and vegetable intake reduces CVD risk. DESIGN: In 1993 we assessed fruit and vegetable intake among 39876 female health professionals with no previous history of CVD or cancer by use of a detailed food-frequency questionnaire. We subsequently followed these women for an average of 5 y for incidence of nonfatal myocardial infarction (MI), stroke, percutaneous transluminal coronary angioplasty, coronary artery bypass graft, or death due to CVD. RESULTS: During 195647 person-years of follow-up, we documented 418 incident cases of CVD including 126 MIs. After adjustment for age, randomized treatment status, and smoking, we observed a significant inverse association between fruit and vegetable intake and CVD risk. For increasing quintiles of total fruit and vegetable intake (median servings/d: 2. 6, 4.1, 5.5, 7.1, and 10.2), the corresponding relative risks (RRs) were 1.0 (reference), 0.78, 0.72, 0.68, and 0.68 (95% CI comparing the 2 extreme quintiles: 0.51, 0.92; P: for trend = 0.01). An inverse, though not statistically significant, trend remained after additional adjustment for other known CVD risk factors, with RRs of 1.0, 0.75, 0.83, 0.80, and 0.85 (95% CI for extreme quintiles: 0.61, 1.17). After excluding participants with a self-reported history of diabetes, hypertension, or high cholesterol at baseline, the multivariate-adjusted RR was 0.45 when extreme quintiles were compared (95% CI: 0.22, 0.91; P: for trend = 0.09). Higher fruit and vegetable intake was also associated with a lower risk of MI, with an adjusted RR of 0.62 for extreme quintiles (95% CI: 0.37, 1.04; P: for trend = 0.07). CONCLUSION: These data suggest that higher intake of fruit and vegetables may be protective against CVD and support current dietary guidelines to increase fruit and vegetable intake.

Age Factors↗