A study of the longitudinal utilization and switching-patterns of non-steroidal anti-inflammatory drugs using a pharmacy based approach

The extent of the heterogeneity of drug utilization among NSAID users has not been extensively studied. We studied the longitudinal prescribing and switching patterns of NSAID users in a 1-year follow-up study in four German pharmacies. The study population consisted of 526 persons with an average age of 57 years. We observed that the legend duration of prescription increased with age; 14.3 days for patients aged 44 or younger to 25.1 days for persons 75 years or older, and was dependent on disease chronicity; 16.0 days for acutely ill persons compared to 23.9 days for chronic patients. The average legend duration also varied between different types of NSAIDs, from 18.0 days for ibuprofen to 29.1 days for tiaprofen. Switching from one type of NSAID to another proved to be related to the legend duration of prescription and patient characteristics such as compliance with NSAID therapy, duration of the disease and the effectiveness (poor tolerability or insufficient effect) of the NSAID therapy reported by the patients 4 weeks after recruitment. We conclude that NSAID users cannot be viewed as an homogeneous group of patients with respect to exposure time to the drug. This heterogeneity should be considered in the exposure definition, the 'time-window' design of observational studies dealing with risk comparisons in particular.

Sample size calculations for single group post-marketing cohort studies

In pharmacoepidemiology, single group cohort is the most frequently proposed design to determine if the incidence rate of an adverse drug reaction among the exposed differs from a reference value. In many situations, the number of events expected in the cohort is too small to conduct sample size calculations based on the normal distribution. This paper proposes, for a single group cohort study, calculations and tables derived from the Poisson distribution. The results are based on a one-sided test with a 0.05 significance level and a power of 0.9 and 0.8. Two parameters have to be specified a priori: the expected incidence of the event under the null hypothesis and the minimum risk ratio to be detected. The required sample size and the critical number of events to reject the null hypothesis are directly derived from the tables. Results show that the normal approximation may lead to an underestimation of the required sample size.

Correlation between dioxin levels in adipose tissue and estimated exposure to Agent Orange in south Vietnamese residents

To permit new epidemiologic studies of the effects of dioxin on humans in Vietnam, we evaluated a model for quantifying exposure to Agent Orange (exposure index) based on the residential histories of 27 Vietnamese subjects and on information about spraying from the U.S. Army records (Herbs Tape) and compared this index to the dioxin levels measured in the subjects' adipose tissue. The mean dioxin level was 7.8 ppt, and dioxin and furan isomer profiles were similar to those already reported in industrialized countries. In addition, there was a highly significant correlation between the levels of almost all the isomers, whatever their degree of chlorination. For the group of 27 subjects, we found a Pearson correlation coefficient of 0.36 (P = 0.07) between the dioxin levels and the exposure index after log-transformation of both variables. When the analysis was restricted to the 22 subjects with a positive exposure index, the Pearson correlation coefficient rose to 0.50 (P = 0.02). We conclude that despite the limitations and power conditions of the study, this result is encouraging because it will be useful for future epidemiologic studies in Vietnam.

Determinants of initiation and suboptimal use of anti-ulcer medication: a study of the Quebec older population

OBJECTIVES

To describe the use of anti-ulcer medication in the Quebec older population; to examine determinants of initiation, suboptimal use, and switches between products.

DESIGN

Population-based retrospective cohort study.

SETTING

Universal health program for older adults in Quebec.

PARTICIPANTS

5000 users and 5000 non-users of anti-ulcer medications were selected randomly. Use was defined as the presence in the 1991 prescription database of an anti-ulcer prescription. Among users, 1697 (34%) were new users and were considered as the exposure group. Subjects were followed for 365 days after inclusion.

MEASUREMENTS

Measured were patient's age, gender, prescribed duration of anti-ulcer medication, concomitant medications, and gastrointestinal diagnostic procedures.

RESULTS

A total of 17% of new users had unusually short courses; 18% were long-term users. There was no difference in duration for omeprazole compared with other anti-ulcer medications. First-time use of NSAIDs was the strongest predictor of initiation of anti-ulcer medication (odds ratio = 3.21; 95% CI, 2.66-3.88). Twenty-six percent of users switched brands. Only 9.5% of new users underwent a diagnostic procedure before initiation of therapy, and 49% of long-term users ever underwent such procedure.

CONCLUSION

Despite a relatively homogeneous recommended duration of therapy, patterns of use of anti-ulcer medication among older people are highly variable, and treatment is often not accompanied by a diagnostic procedure.

Clinical prediction of deep vein thrombosis in patients with leg symptoms

Symptoms and clinical signs individually are inaccurate for the diagnosis of DVT. However, when assessing patients with leg symptoms, clinicians have access to additional information, such as whether or not DVT risk factors are present that could improve the accuracy of clinical judgment. The purpose of this study was to identify which clinical variables best predict DVT, and to use these variables to create a clinical prediction index for DVT. We studied 271 university hospital patients with a first episode of symptomatic, clinically suspected DVT. The prevalence of DVT was 27%, of which 71% were proximal. At baseline, information was collected on demographic features, comorbidity, and symptoms and signs. A Bayesian model selection strategy was used to estimate the logistic regression model that best predicted DVT. Male sex [OR = 2.8 (1.5, 5.1)], orthopedic surgery [OR = 5.4 (2.2, 13.6)], warmth [OR = 2.1 (1.2, 3.9)] and superficial venous dilation on exam [OR = 2.9 (1.4, 5.7)] were independent predictors of DVT. Using the model, a clinical prediction index that categorized patients into different levels of DVT risk was created, and was useful in a theoretical strategy aimed to limit the need for contrast venography in patients with suspected DVT, such that 96% of study patients could have avoided contrast venography. This index should be evaluated prospectively in other patient populations.

Risk factors for development of lower limb pain in adolescents

OBJECTIVE

Although many clinicians believe high growth leads to inflexibility, which may lead to lower extremity pain, the only prospective data suggest growth is unrelated to flexibility. However, it is still possible that growth and/or flexibility are related to pain even if they are not related to each other. We investigated the incidence of leg pain in adolescents to determine whether high growth spurt and/or poor flexibility are risk factors for the development of lower extremity pain.

METHODS

Repeated measures, prospective cohort study of urban high school students aged 12-18. Subjects were measured at baseline and at 6 and 12 months for flexibility of hamstrings and quadriceps and with the sit-and-reach test. Participants completed a detailed questionnaire on recreational activity, occupational activities, psychosocial variables, and musculoskeletal pain.

RESULTS

Poor hamstring flexibility (odds ratio 0.99, confidence interval 0.97-1.01), poor quadriceps flexibility (OR 1.01, CI 0.99-1.03), poor sit-and-reach flexibility (OR 0.99, CI 0.99-1.01), and growth (OR 0.93, CI 0.50-1.71) were not related to the development of lower extremity pain. There was an association between lower extremity pain and occupational activities (OR 2.08, CI 1.45-2.98) and poor mental health (per 1 SD change, OR 1.41, CI 1.19-1.67).

CONCLUSION

Neither growth nor flexibility is related to the development of lower extremity pain in adolescents. A poor mental health score and occupational activities may be associated with the development of lower extremity pain.

[The mission of the Director General of the Ministry of Health]

In France, the health and solidarity department of Employment and solidarity Ministry have just been re-organised. The Directory General of the department of Health is experiencing a complete revision of its functions and organisation. This article presents the public health context which has been taken into account for this new organisation and explains its main principles and strategic orientations. The new organisation chart is clarified. It is made up by two departments and seven under-directions. Up to now, control and administrative supervision were predominant among Health General Direction functions. They are now oriented to administrate missions prioritizing the function of health doctrines' elaboration, of programmation, animation and coordination. As the guarantor of sanitary security, the Health General Direction has also to impulse a new partnership which does not only include health professional, social and health organisation and the economic actors: citizen in general and service users in particular have to be included to promote health democracy.

Importance and economic burden of occupational back pain: a study of 2,500 cases representative of Quebec

The objectives of the study were to estimate the rate of 1-year incidence of occupational back pain, describe the duration of absence from work, and assess medical and economic aspects of this problem. A total of 2,523 files of occupational back pain, representative of the Province of Quebec for the year 1981, were examined by a multidisciplinary team. Census data from 1981 were used for the denominators. The overall 1-year incidence in 1981 was 1.37%. The age-specific incidence rates show an increase-decrease pattern that could be interpreted as a "healthy worker effect". The male to female relative risks by age range from 5.6 (20 to 24 years old) to 1.8 (55 to 64 years old). In the 1-year follow-up, 74% of the workers were absent for less than 1 month. The 7.4% of cases who were absent from work for more than 6 months accounted for nearly 75% of lost days, medical costs, and indemnity payments. We pinpoint some methodologic issues of studies on occupational back pain.

Reduced risk of hospitalisation with risperidone long-acting injectable. Results of the french cohort for the general study of schizophrenia (CGS)

Introduction

Medication non-adherence is a significant risk factor for rehospitalisation in schizophrenia patients. Delayed release formulations like R-LAI may reduce rehospitalisation.

Objectives

To examine the association between R-LAI use and hospitalisation in schizophrenia patients.

Aims

To assess the effect of R-LAI, compared to non-use and use of other antipsychotic drugs, on the risk of hospitalization in real-life settings.

Method

The CGS study recruited schizophrenia patients from 177 public and private wards of psychiatric hospitals across France. Inclusion criteria were schizophrenia (DSM-IV), age 15–65 years, ambulatory/hospitalised for < 93 days at entry. Patients were followed up to 12 months for antipsychotic use and hospitalisation. The recruitment was stratified for long-acting second generation antipsychotic use. Multivariate Poisson regression adjusted for confounding with propensity scores and allowing for autocorrelation was used to estimate relative rates of hospitalisation.

Results

Of 2092 eligible patients, 1859 were included. Their mean age was 38.1 ± 11.1 years, 68.6% were male and 37.8% were hospitalised for < 93 days at entry. A total of 1659 patients (89.2%) were followed up for 12 months, accumulating 933 hospital stays (53.0 per 100 person-years). Compared to other schizophrenia patients, patients on R-LAI were younger, had more often a history of previous hospitalisation for equivalent severity, living conditions and other characteristics. The adjusted relative rate of hospitalisation for R-LAI use against non-use was 0.66 [95% CI 0.46–0.96], and 0.53 [95% CI 0.32–0.88] against long-acting first generation antipsychotics.

Conclusions

Use of R-LAI was associated with lower rates of hospitalization compared to non-use of R-LAI.

Postmarketing surveillance of the safety of cyclic etidronate

To evaluate the safety of cyclic etidronate in routine clinical practice, we obtained information from 550 general practices in the United Kingdom that provide the medical records to the General Practice Research Database. A group of 7977 patients taking cyclic etidronate and two age-, gender-, and practice-matched control groups, one with osteoporosis and one without, were analyzed. For the group taking cyclic etidronate, the average age was 71.6 years and follow-up was 10,328 person-years. Conditions that do not induce osteoporosis generally occurred in these patients at a rate comparable to that in the control groups. The incidence of osteomalacia was low and comparable between patients taking cyclic etidronate and controls with osteoporosis. No medically significant increases in frequency were observed among patients taking cyclic etidronate for a broad group of diseases that may potentially be induced by exposure to the drug. These data support the favorable risk:benefit ratio of cyclic etidronate.

Monitoring of drug utilization in public health surveillance activities: a conceptual framework

The surveillance of individual and aggregate patterns of prescribed medication can potentially provide some very useful information to those involved in public health. At present however, this activity has attracted relatively little attention in Canada. This article will introduce a conceptual framework with which to examine the possibilities of prescription drug monitoring as a tool for public health surveillance. The sources of data available to undertake this activity as well as their limitations, will be presented along with some recent concrete applications.

Chronic venous disorders of the leg: epidemiology, outcomes, diagnosis and management. Summary of an evidence-based report of the VEINES task force. Venous Insufficiency Epidemiologic and Economic Studies

BACKGROUND

To critically review the classification, epidemiology, outcomes, diagnosis and treatment of chronic venous disorders of the leg (CVDL), to issue evidence-based recommendations, and to identify areas requiring further research.

METHODS

Articles identified by an extensive literature search were scored by members of an international task force. Only those articles with a moderate or strong rating for internal validity were retained.

RESULTS

A scoring system weighing CVDL severity according to the probability of ulcer occurrence is proposed. Epidemiological data on the frequency of CVDL and its risk factors are reviewed. The following items are evaluated: costs associated with treatment; clinical outcomes related to CVDL and its treatment; available generic and disease-specific measures of quality of life; diagnostic procedures used to detect venous reflux; and efficacy of available treatments.

CONCLUSIONS

CVDL is an important public health problem, based on its prevalence, cost and impact on quality of life. High-priority areas for research on CVDL are identified.

Links between passive smoking and disease: a best-evidence synthesis. A report of the Working Group on Passive Smoking

We reviewed the toxicologic, clinical, and epidemiologic evidence on the health effects of environmental tobacco smoke (ETS). For each type of exposure to environmental tobacco smoke we have sought articles in the English language reporting studies of effects on human health. Formal criteria that stressed study design, quality of execution and generalizability of results were used to select 116 scientifically admissible reports from over 2,900 articles. We concluded that: (a) there is strong evidence of an association between residential exposure to environmental tobacco smoke and both respiratory illness and reduction of lung function, and also between maternal smoking and reduced birth weight; (b) the weight of evidence is compatible with an association between active maternal smoking during pregnancy and increased infant mortality, and also between residential exposure to environmental tobacco smoke (primarily spousal smoking) and the risk of lung cancer; (c) there is evidence consistent with a relationship between exposure to environmental tobacco smoke in the workplace and respiratory symptoms, (d) the evidence is insufficient to implicate residential exposure to environmental tobacco smoke in relation to other forms of malignant disease or congenital malformations; (e) there is no evidence in the literature of an association between nonresidential exposure to environmental tobacco smoke and any form of cancer. Further studies are required to address the effects of exposure to environmental tobacco smoke, especially nonresidential exposure, in carcinogenesis and as a risk factor for atherosclerosis. Further work is also needed to improve measurement of exposure in such studies and to assess the importance of confounding factors.