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Biomedical subjects

Brian L Strom

Publications and source records attributed to Brian L Strom.

At least 91 records · Page 5Linked to original sources
PubMed2003

Association of regimens of hormone replacement therapy to prognostic factors among women diagnosed with breast cancer aged 50-64 years.

This study was conducted to assess the histopathological features of breast cancers in women diagnosed with breast cancer at 50-64 years of age who have and have not used hormone replacement therapy (HRT). A case-case analysis of the tumors from women aged 50-64 years who participated in a multicenter population-based case-control study of invasive breast cancer was conducted. In-person interviews collected a detailed history of all episodes of hormone use. Information was collected on selected tumor characteristics from 2346 women with breast cancer. Polytomous logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs), contrasting the histopathological characteristics of the tumors of women who used various regimens of HRT with those of women who have never used HRT. The tumors of cases who used each regimen of HRT were smaller and of earlier stage than those of non-HRT users. Adjustment for screening diminished the magnitude of the effect, and only cases who used estrogen alone (estrogen replacement therapy) had reduced odds of being diagnosed with later-stage disease (regional or distant) than cases who never used HRT (OR, 0.7; 95% CI, 0.6-0.9). Higher proportions of estrogen receptor (ER)- and progesterone receptor (PR)-positive tumors were seen in cases who used any regimen of HRT versus those who did not use HRT. However, after adjustment for age and race, only the tumors of cases who used continuous combined HRT remained more likely to be ER+ and PR+ [OR ER- = 0.6 (95% CI, 0.4-0.9) and OR PR- = 0.5 (95% CI, 0.4-0.7)]. The tumors of women with breast cancer who used HRT have some better prognostic factors than those of women who have not used HRT. However, with the exception of the results noted above, this advantage may be due to the racial and age differences in those who use the various regimens of HRT and the effect of more frequent screening among HRT users, leading to earlier diagnosis.

Age Factors↗
PubMed2002

Relation of regimens of combined hormone replacement therapy to lobular, ductal, and other histologic types of breast carcinoma.

BACKGROUND: The incidence of invasive lobular carcinoma has been increasing among postmenopausal women in some parts of the United States. Part of this may be due to changes in classification over time. However, the use of combined (estrogen and progestin) hormone replacement therapy (CHRT) also has increased during the last decade and may account in part for the increase in invasive lobular breast carcinoma. METHODS: A large, multicenter case-control study of Caucasian and African-American women who were diagnosed at age < 65 years with their first invasive breast tumor from July 1, 1994 through April 30, 1998 was conducted. In-person interviews were conducted with 1749 postmenopausal patients, and their responses were compared with the responses of 1953 postmenopausal control women identified through random-digit dialing who met the study criteria of being postmenopausal at the time of diagnosis. Polytomous logistic regression was used to calculate the odds ratio (OR) as an estimate of the relative risk and to compute the 95% confidence interval (95%CI) associated with the use of various regimens of hormone replacement therapy (HRT) among women diagnosed with ductal breast carcinoma, lobular (or mixed lobular and ductal) breast carcinoma, and a grouping of other histologic types of breast carcinoma. RESULTS: Ever use of unopposed estrogen therapy (ERT) was not associated with an increase in the risk of any histologic type of breast carcinoma. The risk of invasive lobular breast carcinoma and the risk of breast carcinoma of the grouping of other histologies increased among women currently using CHRT (OR, 2.2; 95%CI, 1.4-3.3; and OR, 1.9; 95%CI, 1.0-3.4, respectively). The risk increase was greater for the mixed lobular-ductal type than for the pure lobular type of breast carcinoma, although the difference was not statistically significant. There was some indication that >or= 5 years of continuous CHRT (>or= 25 days per month of progestin) was associated with a higher risk of lobular breast carcinoma (OR, 2.5; 95%CI, 1.4-4.3) compared with sequential CHRT (< 25 days per month of progestin; OR, 1.5; 95%CI, 0.8-2.6). Current use of continuous CHRT was only moderately associated with risk of ductal breast carcinoma. CONCLUSIONS: Postmenopausal women who take CHRT appear to be at an increased risk of lobular breast carcinoma. Data from this study suggest that neither ERT use nor CHRT substantially increase the risk of ductal breast carcinoma among women age < 65 years.

Adult↗
PubMed2002

Risk factors for fluoroquinolone resistance in nosocomial Escherichia coli and Klebsiella pneumoniae infections.

BACKGROUND: The incidence of fluoroquinolone (FQ) resistance has increased markedly in recent years. Even in the common nosocomial pathogens Escherichia coli and Klebsiella pneumoniae, in which the emergence of FQ resistance was believed to be unlikely, increasing resistance to these agents has been noted. Risk factors for FQ resistance in these pathogens remain unknown. Although FQs are important components of the present antimicrobial arsenal, their continued usefulness is threatened by rising FQ resistance. OBJECTIVE: To identify risk factors for nosocomial FQ resistance. METHODS: A case-control study of hospitalized patients with infections due to FQ-resistant and FQ-susceptible E coli and K pneumoniae occurring between January 1, 1998, and June 30, 1999. RESULTS: We included 123 patients with nosocomial FQ-resistant infections and 70 randomly selected patients with nosocomial FQ-susceptible infections. Independent risk factors (adjusted odds ratio [95% confidence interval]) for FQ resistance were (1) recent FQ use (5.25 [1.81-15.26]); (2) residence in a long-term care facility (3.65 [1.64-8.15]); (3) recent aminoglycoside use (8.86 [1.71-45.99]); and (4) older age (1.03 [1.01-1.06]). CONCLUSIONS: Recent FQ use, residence in a long-term care facility, recent aminoglycoside use, and older age were all noted to be independent risk factors for FQ resistance among patients with nosocomial E coli and K pneumoniae infections. Efforts should be directed at recognition and modification of these risk factors to curb the rise in FQ resistance and preserve the utility of these agents in the treatment of common nosocomial gram-negative infections.

Adult↗
PubMed2002

Cardiac arrest and ventricular arrhythmia in patients taking antipsychotic drugs: cohort study using administrative data.

OBJECTIVE: To examine the rates of cardiac arrest and ventricular arrhythmia in patients with treated schizophrenia and in non-schizophrenic controls. DESIGN: Cohort study of outpatients using administrative data. SETTING: 3 US Medicaid programmes. PARTICIPANTS: Patients with schizophrenia treated with clozapine, haloperidol, risperidone, or thioridazine; a control group of patients with glaucoma; and a control group of patients with psoriasis. MAIN OUTCOME MEASURE: Diagnosis of cardiac arrest or ventricular arrhythmia. RESULTS: Patients with treated schizophrenia had higher rates of cardiac arrest and ventricular arrhythmia than controls, with rate ratios ranging from 1.7 to 3.2. Overall, thioridazine was not associated with an increased risk compared with haloperidol (rate ratio 0.9, 95% confidence interval 0.7 to 1.2). However, thioridazine showed an increased risk of events at doses > or =600 mg (2.6, 1.0 to 6.6; P=0.049) and a linear dose-response relation (P=0.038). CONCLUSIONS: The increased risk of cardiac arrest and ventricular arrhythmia in patients with treated schizophrenia could be due to the disease or its treatment. Overall, the risk with thioridazine was no worse than that with haloperidol. Thioridazine may, however, have a higher risk at high doses, although this finding could be due to chance. To reduce cardiac risk, thioridazine should be prescribed at the lowest dose needed to obtain an optimal therapeutic effect.

Adult↗
PubMed2002

Provider inaccuracy in assessing adherence and outcomes with newly initiated antiretroviral therapy.

We studied the ability of providers to predict and estimate patient adherence to newly initiated highly active antiretroviral therapy (HAART). Nineteen providers referring 40 patients into an adherence study were surveyed. Widespread inaccuracy was found in providers' adherence predictions and estimates. Therefore, HAART should not be withheld solely on provider predictions of adherence. Providers should not rely on their own assessments when attempting to determine if patients are adhering to therapy.

Adult↗
PubMed2002

Oral contraceptives and the risk of breast cancer.

BACKGROUND: It is uncertain whether the use of an oral contraceptive increases the risk of breast cancer later in life, when the incidence of breast cancer is increased. We conducted a population-based, case-control study to determine the risk of breast cancer among former and current users of oral contraceptives. METHODS: We interviewed women who were 35 to 64 years old. A total of 4575 women with breast cancer and 4682 controls were interviewed. Conditional logistic regression was used to calculate odds ratios as estimates of the relative risk (incidence-density ratios) of breast cancer. RESULTS: The relative risk was 1.0 (95 percent confidence interval, 0.8 to 1.3) for women who were currently using oral contraceptives and 0.9 (95 percent confidence interval, 0.8 to 1.0) for those who had previously used them. The relative risk did not increase consistently with longer periods of use or with higher doses of estrogen. The results were similar among white and black women. Use of oral contraceptives by women with a family history of breast cancer was not associated with an increased risk of breast cancer, nor was the initiation of oral-contraceptive use at a young age. CONCLUSIONS: Among women from 35 to 64 years of age, current or former oral-contraceptive use was not associated with a significantly increased risk of breast cancer.

Adult↗
PubMed2002

Cigarette yield and the risk of myocardial infarction in smokers.

BACKGROUND: Although cigarette smoking is a major risk factor for acute myocardial infarction (MI), cigarette tar yield has not been clearly demonstrated to affect MI risk. METHODS: A case-control study of first MI in smokers aged 30 through 65 years was conducted among 68 hospitals in an 8-county area during a 28-month period. Case subjects were smokers hospitalized at any of the area hospitals with a first MI. Approximately 4 community control smokers per case subject were randomly selected from the same geographic area using random digit dialing. Detailed data on smoking history and cigarette brand were collected. RESULTS: We identified 587 case subjects and 2685 controls who smoked cigarettes with known tar yields. After adjustment using multivariable logistic regression, the odds ratios (ORs) for subjects smoking medium- and high compared with low-tar-yield cigarettes were 1.86 (95% confidence interval [CI], 1.21-2.87) and 2.21 (95% CI, 1.47-3.34), respectively. The adjusted OR increased as tar per day intake increased (P<.001 for the trend); compared with the lowest category of tar per day, the ORs (95% CIs) for increasing tar per day were 1.16 (0.83-1.62), 1.85 (1.35-2.52), 2.42 (1.54-3.78), and 2.50 (1.78-3.52). There was a similar trend of increasing ORs as tar per day increased in smokers of lower-yield cigarettes (P<.001 for the trend) and when low-yield cigarette smokers were excluded (P<.001 for the trend). CONCLUSIONS: Smoking higher-yield cigarettes is associated with an increased risk of MI, and there is a dose-response relationship between total tar consumption per day and MI.

Adult↗
PubMed2002

Parenteral ketorolac and risk of myocardial infarction.

PURPOSE: To examine the effects of ketorolac, a non-aspirin non-steroidal anti-inflammatory drug (NANSAID) with antiplatelet properties, on the risk of in-hospital myocardial infarction (MI). METHODS: A retrospective cohort study was performed among hospitalized patients given 10,219 courses of parenteral ketorolac and patients given 10,145 courses of parenteral opioids, without ketorolac, in 35 hospitals. Patients were matched by hospital, admitting service, and date of study drug initiation. Any MI documented in the chart that occurred during the drug course and up to 3 days after the last dose was recorded by trained abstractors. RESULTS: MI occurred in 18 (0.2%) ketorolac and 45 (0.4%) opioid courses (odds ratio (OR) 0.40, 95% confidence interval (CI) 0.23-0.69). This negative association persisted in multivariable analysis adjusting for age, sex, history of diabetes mellitus or cardiovascular disease, and administration of antiplatelet agents (OR 0.42; 95% CI 0.24-0.73). The association also persisted in numerous analyses excluding patients who may have been treated with analgesics for ischemic pain, and when restricting events to those occurring while on the drug (OR 0.34; 95% CI 0.17-0.69). CONCLUSION: These results are consistent with a protective effect of ketorolac against MI. Future research that implements uniform screening for and independent validation of MIs as well as eliminates possible confounding by indication is the next logical step in confirming these findings.

Adult↗
PubMed2002

Hormone replacement therapy regimens and breast cancer risk(1).

Hormone replacement therapy (HRT) has increased in the United States over the past 2 decades in response to reports of long-term health benefits. A relationship between HRT and breast cancer risk has been observed in a number of epidemiological studies. In 2002, the Women's Health Initiative Randomized Controlled Trial reported an association between continuous combined HRT and breast cancer risk. The objective of this study was to examine the association between breast cancer risk and HRT according to regimen and duration and recency of use.A multicenter, population-based, case-control study was conducted in five United States metropolitan areas from 1994 to 1998. Analyzed were data from 3823 postmenopausal white and black women (1870 cases and 1953 controls) aged 35-64 years. Odds ratios (ORs) were calculated as estimates of breast cancer risk using standard, unconditional, multivariable logistic regression analysis. Potential confounders were included in the final model if they altered ORs by 10% or more. Two-sided P values for trend were computed from the likelihood ratio statistic. Continuous combined HRT was associated with increased breast cancer risk among current users of 5 or more years (1.54; 95% confidence interval 1.10, 2.17). Additionally, a statistically significant trend indicating increasing breast cancer risk with longer duration of continuous combined HRT was observed among current users (P =.01). There were no positive associations between breast cancer risk and other HRT regimens. Our data suggest a positive association between continuous combined HRT and breast cancer risk among current, longer term users. Progestin administered in an uninterrupted regimen may be a contributing factor. Risk dissipates once use is discontinued.

Adult↗
PubMed2002

The incidence and prevalence of pressure ulcers among elderly patients in general medical practice.

PURPOSE: The objective of this study was to estimate the period prevalence and incidence of pressure ulcer among those 65 years of age and older. METHODS: We used a patient-record database called the General Practice Research Database (GPRD). Subjects were 65 years of age and older and cases were ascertained based on strict inclusion and exclusion criteria. The accuracy of the ascertainment strategy was estimated using mailed physician-answered questionnaires. Annual period prevalence and age-specific incidence were estimated per 100 person-years with exact 95% confidence intervals (CI). RESULTS: The accuracy of our ascertainment strategy was excellent, with a positive predictive value of 100% (95% CI: 92%,100%) and negative predictive value of 95% (85%, 95%). Over 200,000 person-years of data were analyzed. The annual period prevalence of pressure ulcer among those 65 years of age and older varied from 0.31% to 0.70%. The incidence varied significantly with advancing patient age from 0.18 to 3.36 per 100-person years (p < 0.001) but was not associated with gender (p = 0.95). CONCLUSIONS: Pressure ulcers are seen in the general practice setting. They are most likely to occur in those over 85 years of age. Preventative strategies within the general practice setting should concentrate on the oldest of the elderly.

Aged↗
PubMed2002

The NICHD Women's Contraceptive and Reproductive Experiences Study: methods and operational results.

PURPOSE: This paper presents methods and operational results of a population-based case-control study examining the effects of oral contraceptive use on breast cancer risk among white and black women aged 35-64 years in five U.S. locations. METHODS: Cases were women newly diagnosed with breast cancer during July 1994 through April 1998. Controls were identified through random digit dialing (RDD) using unclustered sampling with automated elimination of nonworking numbers. Sampling was density-based, with oversampling of black women. In-person interviews were conducted from August 1994 through December 1998. Blood samples were obtained from subsets of cases and controls, and tissue samples were obtained from subsets of cases. A computerized system tracked subjects through study activities. Special attention was devoted to minimizing exposure misclassification, because any exposure-disease associations were expected to be small. RESULTS: An estimated 82% of households were screened successfully through RDD. Interviews were completed for 4575 cases (2953 whites; 1622 blacks) and 4682 controls (3021 whites; 1661 blacks). Interview response rates for cases and controls were 76.5% and 78.6%, respectively, with lower rates for black women and older women. CONCLUSIONS: The methodologic details of this large collaboration may assist researchers conducting similar investigations.

Adult↗
PubMed2002

Statin use and the risk of breast and prostate cancer.

BACKGROUND: Laboratory data suggest that the cholesterol-lowering "statin" drugs may have chemopreventive potential against cancer at various sites, including breast and prostate. However, in one trial of pravastatin there was a significant excess of breast cancer in the treatment group. In the present study, we assessed the relation of statin use to the risk of breast and prostate cancer in our hospital-based Case-Control Surveillance Study of Drugs and Serious Illnesses. METHODS: Cases were 1,132 women with breast cancer and 1,009 men with prostate cancer; controls were 1,331 women and 1,387 men admitted for conditions unrelated to statin use. We used multivariate unconditional logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for use of statins compared with no use. RESULTS: The OR for breast cancer among statin users was 1.5 (95% CI = 1.0-2.3), largely accounted for by an OR of 1.8 (95% CI = 0.9-3.6) among cases with carcinoma in situ. Among invasive cases, the OR was 1.2 (95% CI = 0.7-2.0). The odds ratio for prostate cancer overall was 1.2 (95% CI = 0.8-1.7), and it was 1.4 (95% CI = 0.7-2.5) for Stage A. CONCLUSIONS: The data from the present study do not support a protective effect of statins against breast or prostate cancer. Detection bias is a possible explanation for the higher ORs observed for carcinoma in situ or early-stage cancer as compared with more invasive cancer.

Aged↗
PubMed2002

Hospitalization and mortality rates from peptic ulcer disease and GI bleeding in the 1990s: relationship to sales of nonsteroidal anti-inflammatory drugs and acid suppression medications.

OBJECTIVES: Nonsteroidal anti-inflammatory drugs (NSAIDs) can cause peptic ulcer disease and upper GI bleeding. Acid suppression medications effectively treat NSAID-induced ulcers. However, it is unknown what effect the availability of proton pump inhibitors and over-the-counter preparations of NSAIDs and histamine type 2 receptor antagonists have had on population rates of hospitalization and mortality from GI toxicity. This study examines trends in hospitalization and mortality rates from GI toxicity during the 1990s. METHODS: We performed an analysis of secular trends of hospitalization and mortality rates from peptic ulcer disease, upper GI bleeding, and any GI bleeding using data from the National Hospital Discharge Survey, comparing them with sales of NSAIDs, aspirin, and acid suppression medications from 1992 to 1999. RESULTS: From 1992 to 1999, annual rates of hospitalization and mortality per 100,000 population for peptic ulcer disease declined from 205 to 165 and 7.7 to 6.0, respectively; calendar year was negatively correlated with both peptic ulcer disease hospitalization rates (p = -0.88, p = 0.007) and mortality rates (p = -0.71, p = 0.058). In contrast, these correlations did not reach statistical significance for upper or any GI bleeding (p > 0.1 for all comparisons). Sales of acid suppression medications were negatively correlated with peptic ulcer disease hospitalization rates (p = -0.76, p = 0.037) and mortality rates (p = -0.83, p = 0.015). Sales of NSAIDs were not positively correlated with hospitalization or mortality rates from peptic ulcer disease or GI bleeding (p > 0.2 for all comparisons). CONCLUSIONS: Despite changing patterns of use of NSAIDs and acid suppression medications during the 1990s, mortality rates from GI bleeding and peptic ulcer disease have been relatively stable, with an apparent decline in hospitalization rates and mortality from peptic ulcer disease. Changing rates of peptic ulcer disease morbidity and mortality were temporally related to increasing sales of antiulcerants but not to change in sales of NSAIDs.

Antacids↗
PubMed2002

Do thyroid disorders increase the risk of breast cancer?

The objective of this study was to determine whether thyroid disorders or treatment of such disorders affects the risk of breast cancer. Subjects aged 35-64 years were participants in the National Institute of Child Health and Human Development Women's Contraceptive and Reproductive Experiences Study, a population-based, case-control study of invasive breast cancer that was carried out at five sites in the United States. In-person interviews were completed for 4575 women (cases) with breast cancer (2953 white and 1622 black) and 4682 control women (3021 white and 1661 black). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multiple logistic regression methods. Models included adjustment for age (5-year age groups), race (white or black), and site. A history of any thyroid disorder (OR = 1.1, 95% CI = 0.9-1.2) was not associated with breast cancer risk. Only women with a history of thyroid cancer had an increased risk, but this was restricted to parous women (parous OR = 3.4, 95% CI = 1.5-8.1; nulliparous OR = 0.5, 95% CI = 0.04-5.1). Breast cancer risk was not associated with treatment for thyroid disorders. There was no statistical interaction between thyroid disorders, thyroid treatments, and race, menopausal status, or parity. We found no association between thyroid disorders or their associated treatments and the risk of breast cancer.

Adult↗
PubMed2000

Defining the clinically important difference in pain outcome measures.

The purpose of this study was to determine the levels of change on standard pain scales that represent clinically important differences to patients. Data from analgesic studies are often difficult to interpret because the clinical importance of the results is not obvious. Differences between groups, as summarized by a change in mean values over time, can be difficult to apply to clinical care. Baseline scores vary widely and group mean differences could reflect large changes in a few patients, small changes in many patients, or any combination of these outcomes. Determination of the proportion of patients who have a clinically important improvement in their pain would provide a more interpretable result with direct clinical implications. However, determining a clinically important outcome requires information about the degree of change over time that is clinically important. Data from the titration phase of a multiple cross-over randomized clinical trial of oral transmucosal fentanyl citrate (OTFC) for the treatment of cancer-related breakthrough pain were re-analyzed to examine the differences in pain scores between treatment episodes that did and did not yield adequate pain relief. The scales evaluated were absolute pain intensity difference (PID, 0-10 scale), percentage pain intensity difference (PID%, 0-100% scale), pain relief (PR, 0 (none), 1 (slight), 2 (moderate), 3 (lots), 4 (complete)), sum of the pain intensity difference (SPID over 60 min), percentage of maximum total pain relief (% Max TOTPAR over 60 min), and global medication performance (0 (poor), 1 (fair), 2 (good), 3 (very good), 4 (excellent)). Adequate relief was defined by the patient's decision not to use another dose of opioid medication as a rescue, in addition to the study medication, to treat each painful episode. One hundred thirty OTFC naive patients contributed data on 1268 episodes of breakthrough pain. The scales that were converted to a percentage change yielded the best accuracy in predicting adequate relief, with balanced sensitivity and specificity. The best cut-off point for both the % Max TOTPAR and the PID% was 33%. The best cut-off points for the absolute scales were absolute pain intensity difference of 2, pain relief of 2 (moderate), and SPID of 2. The global medication performance of 2 (good) had excellent values as well. This study presents data-derived cut-off points for the changes in several pain scales, each reflecting the clinically important improvement for patients treating breakthrough cancer pain episodes with OTFC. Confirmation in other patient populations and different pain syndromes will be needed. The use of consistent clinically important cut-off points as the primary outcome in future pain therapy clinical trials will enhance their validity, comparability, and clinical applicability.

Analgesics, Opioid↗
PubMedDate not supplied

Validity and completeness of the General Practice Research Database for studies of inflammatory bowel disease.

PURPOSE: The objective of this study was to evaluate the validity and completeness of the General Practice Research Database (GPRD) as a tool for research into inflammatory bowel disease epidemiology. METHODS: Patients diagnosed with inflammatory bowel disease were identified from GPRD. Mailed surveys were sent to the general practitioner caring for a stratified random sample of 170 of these patients and collected information on the diagnosis of inflammatory bowel disease and the most recent surgery and hospitalization. RESULTS: Usable surveys were returned for 157 patients (92%). The inflammatory bowel disease diagnosis was highly probable or probable in 144 (92%, 95% CI 86 to 96%). Among the 53 patients with a potentially incident inflammatory bowel disease diagnosis, 33 (62%) had the first recorded diagnosis in GPRD within 30 days of the date reported in the survey (median difference -8 days; interquartile range 0 to -81 days). Of 12 surgeries and 25 hospitalizations reported in the survey, 11 (92%) and 19 (76%) were identified in GPRD, respectively. CONCLUSIONS: The diagnosis of inflammatory bowel disease in GPRD appears reliable for most patients. Important medical events such as hospitalizations and surgery are recorded at a high rate, although algorithms to identify these events are complex.

Cohort Studies↗