A comparison of the use, effectiveness and safety of bezafibrate, gemfibrozil and simvastatin in normal clinical practice using the New Zealand Intensive Medicines Monitoring Programme (IMMP).
AIMS: Because of the importance of treating dyslipidaemia in the prevention of ischaemic heart disease and because patient selection criteria and outcomes in clinical trials do not necessarily reflect what happens in normal clinical practice, we compared outcomes from bezafibrate, gemfibrozil and simvastatin therapy under conditions of normal use. METHODS: A random sample of 200 patients was selected from the New Zealand Intensive Medicines Monitoring Programme's (IMMP) patient cohorts for each drug. Questionnaires sent to prescribers requested information on indications, risk factors for ischaemic heart disease, lipid profiles with changes during treatment and reasons for stopping therapy. RESULTS: 80% of prescribers replied and 83% of these contained useful information. The three groups were similar for age, sex and geographical region, but significantly more patients on bezafibrate had diabetes and/or hypertension than those on gemfibrozil or simvastatin. After treatment and taking the initial measure into account, the changes in serum lipid values were consistent with those generally observed, but with gemfibrozil being significantly less effective than expected. More patients (15.8%S) stopped gemfibrozil because of an inadequate response compared with bezafibrate (5.4%) and simvastatin (1.6%). Gemfibrozil treatment was also withdrawn significantly more frequently due to a possible adverse reaction compared with the other two drugs. CONCLUSIONS: In normal clinical practice in New Zealand gemfibrozil appears less effective and more frequently causes adverse effects leading to withdrawal of treatment than either bezafibrate or simvastatin. (+info)
Record-linkage for pharmacovigilance in Scotland.
Record-linkage is the linkage of patient-specific information that is stored separately. Recent advances in computerization have meant that record-linkage techniques in medical research are increasingly being used and refined. In particular, they have made a significant contribution to pharmacovigilance, which involves linking drug exposure to outcomes data. In this article, the contribution of record-linkage in Scotland to medical research is described. The two organizations that utilize record-linkage techniques are the Medicines Monitoring Unit (MEMO) of the University of Dundee and the Information and Statistics Division (ISD) of the NHS in Scotland. Pharmacovigilance is MEMO's main concern (using data from the Tayside region of Scotland), while ISD link health care datasets for Scotland for general health care research. The experience of the two groups is now being combined to carry out drug safety studies in the entire population of Scotland. (+info)
Efficacy of Haemophilus influenzae type b conjugate vaccines and persistence of disease in disadvantaged populations. The Haemophilus Influenzae Study Group.
OBJECTIVES: The purpose of this study was to evaluate the effectiveness of Haemophilus influenzae type b (Hib) conjugate vaccines among children aged 2 to 18 months and to determine risk factors for invasive Hib disease during a period of declining incidence (1991-1994). METHODS: A prospective population-based case-control study was conducted in a multistate US population of 15.5 million. A laboratory-based active surveillance system was used for case detection. RESULTS: In a multivariate analysis, having a single-parent mother (odds ratio [OR] = 4.3, 95% confidence interval [CI] = 1.2, 14.8) and household crowding (OR = 3.5, 95% CI = 1.03, 11.7) were risk factors for Hib disease independent of vaccination status. After adjustment for these risk factors, the protective efficacy of 2 or more Hib vaccine doses was 86% (95% CI = 16%, 98%). Among undervaccinated subjects, living with a smoker (P = .02) and several indicators of lower socioeconomic status were risk factors for Hib disease. CONCLUSIONS: Hib disease still occurs at low levels in the United States, predominantly in socioeconomically disadvantaged populations. Low immunization coverage may facilitate continuing transmission of Hib. Special efforts to achieve complete and timely immunization in disadvantaged populations are needed. (+info)
Postmarketing analysis of lovastatin use in the VA Northern California System of Clinics: a retrospective, computer-based study.
Prevention of coronary heart disease is a major public health goal. The efficacy of lovastatin in lowering serum cholesterol has been proven in research studies, but its efficacy in practice is unclear. To evaluate our practice patterns and outcome in the Veterans Administration Northern California System of Clinics, we reviewed computer-based records of 203 unselected patients issued lovastatin; 193 (95%) were men, and the average patient age was 66 +/- 9 years. The average daily dose of lovastatin was 24 +/- 10 mg, and average duration of therapy was 22 +/- 11 months. Only 72 patients (35%) were instructed on the prescription to take their medication with the evening meal, and only 59 patients (29%) had seen a dietitian during the observed (1 to 3 years) treatment period. Nevertheless, among the 124 patients with pretreatment lipid data, total serum cholesterol decreased by 18% from 271 +/- 45 to 221 +/- 41 mg/dL (P < 0.001), and low density lipoprotein (LDL)-cholesterol decreased by 23% from 185 +/- 43 to 143 +/- 37 (P < 0.001) mg/dL. High density lipoprotein-cholesterol and triglycerides were unchanged. Of the 168 patients with LDL-cholesterol data during the treatment period, only 74 (44%) achieved an LDL-cholesterol level of less than 130 mg/dL, the minimum goal for a population of older males with a high incidence of other cardiac risk factors. Safety surveillance with liver function testing was performed at least once in 192 patients (95%), but with creatine phosphokinase (CPK) testing in only 123 patients (61%) during the survey period. Enzyme elevations were minor, but occurred at least intermittently in approximately one quarter of patients. Only 5.7% of patients on lovastatin manifested an increase in transaminases on therapy. Due to incomplete baseline data, it is unclear how many patients had elevated CPK as a result of lovastatin. We conclude that: (1) lovastatin is effective in lowering total and LDL-cholesterol in practice, but is often used in dosage insufficient to lower LDL-cholesterol to goal levels; (2) patients are not being adequately educated on dosing schedules; (3) toxicity may be underestimated by infrequent and inconsistent surveillance; and (4) nonpharmacologic therapy is underutilized. (+info)
Medical records and privacy: empirical effects of legislation.
OBJECTIVE: To determine the effects of state legislation requiring patient informed consent prior to medical record abstraction by external researchers for a specific study. DATA SOURCES/STUDY SETTING: Informed consent responses obtained from November 1997 through April 1998 from members of a Minnesota-based IPA model health plan. STUDY DESIGN: Descriptive case study of consent to gain access to medical records for a pharmaco-epidemiologic study of seizures associated with use of a pain medication that was conducted as part of the FDA's post-marketing safety surveillance program to evaluate adverse events associated with approved drugs. DATA COLLECTION: The informed consent process approved by an institutional review board consisted of three phases: (1) a letter from the health plan's medical director requesting participation, (2) a second mailing to nonrespondents, and (3) a follow-up telephone call to nonrespondents. PRINCIPAL FINDINGS: Of 140 Minnesota health plan members asked to participate in the medical records study, 52 percent (73) responded and 19 percent (26) returned a signed consent form authorizing access to their records for the study. For 132 study subjects enrolled in five other health plans in states where study-specific consent was not required, health care providers granted access to patient medical records for 93 percent (123) of the members. CONCLUSION: Legislation requiring patient informed consent to gain access to medical records for a specific research study was associated with low participation and increased time to complete that observational study. Efforts to protect patient privacy may come into conflict with the ability to produce timely and valid research to safeguard and improve public health. (+info)
Demographic, dietary and lifestyle factors differentially explain variability in serum carotenoids and fat-soluble vitamins: baseline results from the sentinel site of the Olestra Post-Marketing Surveillance Study.
Biochemical measures of nutrients or other dietary constituents can be an important component of nutritional assessment and monitoring. However, accurate interpretation of the nutrient concentration is dependent on knowledge of the determinants of the body pool measured. The purpose of this study was to identify the determinants of serum carotenoid and fat-soluble vitamin concentrations in a large, community-based sample (n = 1042). Multiple linear regression analysis was used to examine effects of demographic characteristics (age, sex, race/ethnicity, education), health-related behavior (exercise, sun exposure, smoking, alcohol consumption), and intake (diet, supplements) on serum retinol, 25-hydroxyvitamin D, alpha-tocopherol, phylloquinone, and carotenoid concentrations. Age, sex, race/ethnicity, vitamin A intake, and alcohol consumption were found to be determinants of serum retinol concentration. Race/ethnicity, vitamin D intake, body mass index, smoking status, and sun exposure were determinants of serum 25-hydroxyvitamin D concentration. Determinants of serum alpha-tocopherol were age, sex, race/ethnicity, alpha-tocopherol intake, serum cholesterol, percentage of energy from fat (inversely related), supplement use, and body mass index. Age, sex, phylloquinone intake, serum triglycerides, and supplement use were determinants of serum phylloquinone concentration. Primary determinants of serum carotenoids were age, sex, race/ethnicity, carotenoid intake, serum cholesterol, alcohol consumption, body mass index, and smoking status. Overall, the demographic, dietary, and other lifestyle factors explained little of the variability in serum concentrations of retinol (R2 = 0.20), 25-hydroxyvitamin D (R2 = 0.24), and the carotenoids (R2 = 0.15-0.26); only modest amounts of the variability in serum phylloquinone concentration (R2 = 0.40); and more substantial amounts of the variability in serum alpha-tocopherol concentration (R2 = 0.62). (+info)
Is reporting rate a good predictor of risks associated with drugs?
AIMS: Uncertainty as to relative under-reporting plagues the comparisons of spontaneous reporting rates as a tool for decision-making in pharmacovigilance. However, it is generally accepted that under-reporting should be reasonably similar for similar drugs sharing the same indication, country and period of marketing. To test this, we compared the adverse drug reaction reporting rates to the French regional pharmacovigilance centres for six pairs of identical drug marketed at the same time by different companies under different brand names (co-marketing). METHODS: All reaction reports were related to sales, to compute reporting rate; within each pair, the reporting rate ratio and its confidence interval were calculated. RESULTS: The rate ratios were all between 0.76 and 1.33. Two of them were significantly different from 1 (1.28; 95% C.I. [1.01; 1.60] and 1.33; 95% C.I. [1.06; 1.74]). CONCLUSIONS: These small differences in reporting rates would not warrant regulatory action and support the usual assumption of similar reporting for similar drugs. (+info)
Safety and efficacy of fertility-regulating methods: a decade of research.
An international venture was launched in 1985 to fill a recognized gap in post-marketing surveillance of fertility-regulating methods. For this purpose a new task force was set up by the Special Programme of Research, Development, and Research Training in Human Reproduction, which is cosponsored by the United Nations Development Programme, the United Nations Population Fund, the World Bank, and WHO. Research priorities were chosen and epidemiological studies inaugurated, involving a total of 47 countries--mostly from the developing world. Important progress has been made, especially in helping to define the beneficial and possible adverse effects of oral contraceptives on the risk of neoplasia; in showing that the injectable contraceptive depot-medroxyprogesterone acetate protects against endometrial cancer and does not increase the overall risk of breast cancer, in clarifying which groups of women are susceptible to the rare cardiovascular complications of oral contraceptives (myocardial infarction, stroke, and venous thromboembolism); and in establishing the long-term effectiveness and safety of intrauterine devices. The research has already made a significant impact on family planning policies and practice. Critical appraisal of this venture, which has been modestly funded, confirms the value of mission-oriented research. It also illustrates the potential of collaboration that bridges the global divide between developing and developed countries. (+info)