Primary non-compliance with prescribed medication in primary care.

OBJECTIVE: To determine the rate of patients not redeeming their prescriptions (primary noncompliance) and assess the factors influencing this. DESIGN: Observational study comparing copies of prescriptions written by general practitioners with those dispensed by pharmacists and subsequent case record review. SETTING: A large rural general practice in Tayside. SUBJECTS: All 4854 patients who received prescriptions (20,921) written between January 1989 and March 1989. MAIN OUTCOME MEASURES: The rate of non-redemption of prescriptions. RESULTS: Seven hundred and two patients (14.5%) did not redeem 1072 (5.2%) prescriptions during the study period, amounting to 11.5% of men and 16.3% of women. Non-redemption was highest in women aged 16-29 (27.6% of women) and men aged 40-49 (18.3% of men). Of prescriptions issued to women for oral contraceptives 24.8% were not redeemed during the study period. In those who redeemed prescriptions 17% were not exempt from prescription charges compared with 33% of patients who failed to redeem them. The non-redemption rate was highest for prescriptions issued at the weekends, although this was a small proportion of all prescribing. Prescriptions issued by trainee general practitioners were also less likely to be redeemed. CONCLUSIONS: Non-redemption varies with age, sex, general practitioner, exemption status, and with day of the week the prescription was written. Observational studies of drug exposure can be more accurately estimated from dispensing rather than prescribing data.

The risks of symptomatic vaginal candidiasis after oral antibiotic therapy.

It is generally accepted that antibiotic use can result in vaginal fungal overgrowth, although evidence estimating the extent to which this causes symptomatic vaginitis is scant. In a study using the prescription of vaginal antifungal preparations as a surrogate measure of vaginal candidiasis, a cohort of women taking antibiotics had a higher incidence of vaginal candidiasis after antibiotic exposure than beforehand (relative risk 2.3; 95% confidence interval 1.9-3.0); this risk was highest in those aged 36-40 years (RR 6.0, 95% CI 2.9-12.5). The attributable risk was highest among those who were taking cephalosporins (AR 12.8%, 95% CI 9.1-16.5). In a case-control study, comparing previous antibiotic exposure among women using vaginal antifungal agents and matched controls, antibiotic exposure was higher among those using vaginal antifungal agents during the previous 28 days, with an odds ratio of 5.5 (95% CI 3.8-7.9).

General practitioners' use of non-steroidal anti-inflammatory drugs in Tayside and Fife regions.

The objectives of this study were to assess the prescribing of non-steroidal anti-inflammatory drugs (NSAIDs) by general practitioners and to determine their attitudes to problems caused by this class of drugs. The study consisted of two parts. The first was a questionnaire survey among general practitioners in Fife and Tayside, and the second was an analysis of NSAID prescribing over 12 months among the doctors in the Carnoustie Health Centre, using duplicate prescriptions. In the questionnaire survey 61% of the general practitioners responded. The three most preferred drugs were buprofen (56%), naproxen (20%) and mefenamic acid (7%); choice of drug was determined by efficacy and personal experience. Gastrointestinal side effects were most frequently encountered, although there was little consensus amongst respondents as to their management. The duplicate prescription study showed that 14% of patients (1607 individuals) received at least one NSAID prescription in the year of study. Ibuprofen (31%), naproxen (20%) and piroxicam (15%) were most frequently prescribed and up to 16% of the patients were co-prescribed a gastroprotective agent; ranitidine (75%) was the most commonly prescribed. Despite the introduction of newer NSAIDs, ibuprofen and naproxen are still the most commonly prescribed drugs. Furthermore, although gastrointestinal side effects are commonly encountered, there is some uncertainty about their management.

Gastrointestinal events in patients prescribed non-steroidal anti-inflammatory drugs: a controlled study using record linkage in Tayside.

The relationship between non-steroidal anti-inflammatory drugs (NSAIDs) and gastrointestinal events has been examined in Tayside by record linkage. From March to October 1983, 57 715 prescriptions for five NSAIDs (ibuprofen, indomethacin, naproxen, Osmosin and piroxicam) were issued to 25 959 patients. Their inpatient morbidity from 1 January 1983 to 31 December 1985 was compared to that of an equal number of control subjects matched for age, sex and general practitioner. Analysis revealed that NSAID takers were more likely to develop disease of the gastrointestinal system (ICD 520-579) and symptoms involving the gastrointestinal system (ICD 787). For females the relative risk was 1.67 and for males 1.28. The difference between NSAID takers and controls increased with age above 60 years and was more pronounced over 70 years. Perforation and haemorrhage of peptic ulcer and gastrointestinal haemorrhage was also higher among NSAID takers after prescription: this difference was dependent upon age but not related to sex. The morbidity of the two groups, control and subsequent NSAID takers, was comparable before the NSAID prescriptions were issued and the control rates remained constant throughout the study.

Introducing a drug formulary to general practice--effects on practice prescribing costs.

A drug formulary comprising 249 preparations of 132 drugs and drug combinations was prepared by the partners in a three-doctor general practice serving more than 5000 patients. No attempt was made to change to generic prescribing nor were repeat prescription drugs altered. Introduction of the formulary in September 1981 was followed by an increase in the proportion of prescriptions containing drugs from the formulary from about 55% to more than 60% for both repeat and non-repeat prescriptions. The proportion of formulary drugs on non-repeat prescriptions reached a maximum of 78% within the first year with the additional influence of information feedback. Over the first year the level of formulary drugs used for both repeat and nonrepeat prescribing levelled off at about 62%. Even with these modest changes, when compared with the costs of general practice prescribing in Scotland as a whole, the introduction of the formulary resulted in savings of approximately 10% within the practice for the mean ingredient costs both per patient and per prescription.