James Bashford

Why are patients prescribed proton pump inhibitors? Retrospective analysis of link between morbidity and prescribing in the General Practice Research Database.

Abstract Objectives: To establish the relation between new prescriptions for proton pump inhibitors and recorded upper gastrointestinal morbidity within a large computerised general practitioner database. Design: Retrospective survey of morbidity and prescribing data linked to new prescriptions for proton pump inhibitors and comparison with licensed indications between 1991 and 1995. Setting: General Practice Research Database and prescribing analysis and cost (PACT) data for the former West Midlands region. Subjects: Information for 612 700 patients in the General Practice Research Database. Anonymous PACT data for all general practitioners in West Midlands region. Main outcome measures: Diagnostic codes linked to the first prescriptions issued for proton pump inhibitors; relation between new prescriptions and licensed indications; yearly change in ratio of new to repeat prescriptions and prescribing volumes measured as defined daily doses. Results: Oesophagitis was the commonest recorded indication in 1991, accounting for 31% of new prescriptions, but was third in 1995 (14%). During the study new prescriptions increased substantially, especially for duodenal disease (780%) and non-ulcer dyspepsia (690%). In 1995 non-specific morbidity accounted for 46% of new prescriptions. The total volume of prescribing rose 10-fold between 1991 and 1995, when repeat prescribing accounted for 77% of the total. Conclusions: Changes in recorded morbidity associated with new prescriptions of proton pump inhibitors did not necessarily reflect changes in licensed indications. Although general practitioners seemed to respond to changes in licensing, particularly for duodenal and gastric disease, prescribing for unlicensed indications non-ulcer dyspepsia and non-specific abdominal pain increased. Key messages There has been much speculation about the reasons behind the substantial rise in prescribing of proton pump inhibitors, especiallytheir use for minor symptoms. We used the General Practitioner Research Database for the former West Midlands region to show that the volume of proton pump in hibitorprescribing rose 10-fold between 1992 and 1995 and repeatprescribing had risen to 77% of the volume by 1995 Prescribing for uncomplicated dyspepsia and non-specific abdominalsymptoms, which were outside the licensed indications, accounted for 46%of new prescribing by 1995 The proportion of prescribing for the licensed indication ofoesophagitis fell during the study, but that for duodenal ulcerationincreased in line with the expansion of licensed indications Analysis of PACT data showed similar prescribing trends to thosefound with the General Practitioner Research Database

Effect of anxiolytic and hypnotic drug prescriptions on mortality hazards: retrospective cohort study.

Objective To test the hypothesis that people taking anxiolytic and hypnotic drugs are at increased risk of premature mortality, using primary care prescription records and after adjusting for a wide range of potential confounders. Design Retrospective cohort study. Setting 273 UK primary care practices contributing data to the General Practice Research Database. Participants 34 727 patients aged 16 years and older first prescribed anxiolytic or hypnotic drugs, or both, between 1998 and 2001, and 69 418 patients with no prescriptions for such drugs (controls) matched by age, sex, and practice. Patients were followed-up for a mean of 7.6 years (range 0.1-13.4 years). Main outcome All cause mortality ascertained from practice records. Results Physical and psychiatric comorbidities and prescribing of non-study drugs were significantly more prevalent among those prescribed study drugs than among controls. The age adjusted hazard ratio for mortality during the whole follow-up period for use of any study drug in the first year after recruitment was 3.46 (95% confidence interval 3.34 to 3.59) and 3.32 (3.19 to 3.45) after adjusting for other potential confounders. Dose-response associations were found for all three classes of study drugs (benzodiazepines, Z drugs (zaleplon, zolpidem, and zopiclone), and other drugs). After excluding deaths in the first year, there were approximately four excess deaths linked to drug use per 100 people followed for an average of 7.6 years after their first prescription. Conclusions In this large cohort of patients attending UK primary care, anxiolytic and hypnotic drugs were associated with significantly increased risk of mortality over a seven year period, after adjusting for a range of potential confounders. As with all observational findings, however, these results are prone to bias arising from unmeasured and residual confounding.

Why are eligible patients not prescribed aspirin in primary care? A qualitative study indicating measures for improvement

BackgroundDespite evidence-based guidelines, aspirin prescribing for the secondary prevention of stroke is sub-optimal. Little is known about why general practitioners do not prescribe aspirin to indicated patients. We sought to identify and describe factors that lead general practitioners (GPs) not to prescribe aspirin to eligible stroke patients. This was the first stage of a study exploring the need for and means of improving levels of appropriate aspirin prescribing.MethodQualitative interviews with 15 GPs in the West Midlands.ResultsInitially, many GPs did not regard their prescribing as difficult or sub-optimal. However on reflection, they gave several reasons that lead to them not prescribing aspirin for eligible patients or being uncertain. These include: difficulties in applying generic guidelines to individuals presenting in consultations, patient resistance to taking aspirin, the prioritisation of other issues in a time constrained consultation and problems in reviewing the medication of existing stroke patients.ConclusionIn order to improve levels of appropriate aspirin prescribing, the nature and presentation risk information available to GPs and patients must be improved. GPs need support in assessing the risks and benefits of prescribing for patients with combinations of complicating risk factors, while means of facilitating improved GP-patient dialogue are required to help address patient uncertainty. A decision analysis based support system is one option. Decision analysis could synthesise current evidence and identify risk data for a range of patient profiles commonly presenting in primary care. These data could then be incorporated into a user-friendly computerised decision support system to help facilitate improved GP-patient communication. Measures of optimum prescribing based upon aggregated prescribing data must be interpreted with caution. It is not possible to assess whether low levels of prescribing reflect appropriate or inappropriate use of aspirin in specific patients where concordance between the GP and the patient is practised.

Ratio of Inhaled Corticosteroid to Bronchodilator Treatment and Asthma Hospitalisation

Summary Background: Previous research based on aggregated data has led to conflicting interpretations of the relationship between the corticosteroid:bronchodilator (C:B) ratio and outcome measures. Objectives: To assess whether the C:B ratio is associated with hospital contact for asthma at individual patient level. Methods: The study was a retrospective multivariate analysis, using data from the UK General Practice Research Database from 1993 to 1996. The subjects were 3465 asthma-diagnosed patients receiving bronchodilator and corticosteroid medication. The main outcome measures were asthma-related hospital contacts. Results: There was an inverse association between the C:B ratio and hospital contact after controlling for age. The odds ratio for the C:B ratio was 0.87 (95% CI 0.73–0.98) and 1.04 (95% CI 1.01–1.07) for five-year agebands among patients aged five years and over. There was no systematic relationship between the C:B ratio and hospital contacts for patients aged under five years. Conclusion: The results of this study show that higher C:B ratios are associated with lower levels of hospital contacts at patient level, although there are exceptions possibly linked to disease severity. For patients under five years, the ratio may not be a good outcome measure, perhaps owing to the difficulty in diagnosing asthma or poor compliance.

Social deprivation and patterns of consultation for respiratory symptoms: a population-based cohort study.

1increased asthma mortality, 2 and greater severity of asthmatic symptoms 3 have been observed in relation to social class and geographical deprivation. By contrast the prevalence of symptoms such as wheeze has not been consistently found to vary with social class. 3‐5 One explanation of these conflicting observations is that people from deprived backgrounds with respiratory symptoms may be less prone to seek or comply with health care. In the United Kingdom, consultations in general practice are one measure of seeking health care. We have carried out a study to determine whether people with respiratory symptoms from deprived areas consult more or less often than those from aZuent areas.

The role of cannabis and cannabinoids in diabetes

This paper reviews the role of cannabis in diabetes. Cannabis is by far the most commonly used illicit drug in Britain, though its use may be declining. There are an estimated 50,000–100,000 people with dia betes using cannabis, with an unknown number using the drug for self-medication. The evidence of the effects of cannabis on diabetes is complex, ranging from anecdotal reports of benefits and harms to experimental research on cannabinoids. The endocannabinoid system appears to have a role in the regulation of body weight and food intake, and the development of hyperglycaemia, insulin resistance and dyslipidaemia. In experimental models, the main psychoactive constituent of herbal cannabis, Δ9-tetrahydrocannabinol, has been shown to interfere with both the action of insulin and its release. The paper also considers the effects of cannabis on complications of diabetes. Experimental work has suggested a mechanism to reduce neuropathy but the only double-blind clinical trial to date of a cannabisbased drug found no difference in the ability of the cannabis-based product to relieve neuropathic pain when compared with placebo. In conclusion, new insights into the role of cannabis and cannabinoids in diabetes are emerging from this developing field of research. Br J Diabetes Vasc Dis 2010;10:267-273.

How to Apply Pharmacoeconomic Principles to Local Settings

SummaryApplication of pharmacoeconomic principles to local settings requires an understanding of the subject matter of pharmacoeconomics. Pharmacoeconomics is the application of economics to the evaluation of healthcare interventions. It seeks to broaden the rational scientific basis for making choices between alternative forms of healthcare interventions by capturing and relating their costs and outcomes. Capturing costs requires addressing each form of cost and where they fall. An outcome of treatment implies a change in health status which can be identified and measured using health outcome instruments. Combining costs and outcomes in an analysis will indicate whether a particular healthcare intervention represents good value for money. The type of analysis used to relate costs and outcomes (e.g. cost-minimisation, cost-effectiveness, cost-benefit, cost-utility) will depend on the number, magnitude and distribution of the outcomes.Pharmacoeconomic analysis can, and should, form part of clinical trials comparing different forms of treatment intervention, considering that the efficiency of a healthcare intervention in practice may differ from its apparent efficacy in the clinical trial. Pharmacoeconomic principles can also be applied to clinical dilemmas using modelling techniques that do not involve studying patients directly. Future costs and benefits can be brought to present-day values using the method of discounting. Sensitivity analysis allows the ‘crystal ball’ to be applied to a variety of local settings.This paper enables those who are faced with pharmacoeconomic assessments to be more vigilant and critical of the techniques used and the assumptions made. This paper also leads to a wider recognition of the importance of economics in clinical decision-making and encourages the incorporation of pharmacoeconomic analysis into the options available.Throughout the paper, emphasis is placed on offering insight and inspiration to the tools, tips and traps of applying pharmacoeconomics to local settings. Examples from the published literature are used to signal the relevance and importance of pharmacoeconomics.

Determining patient characteristics for decision analysis support systems using anonymized electronic patient records.

While decision analysis has the potential to improve treatment decisions, the quality of patient specific data has hindered its development. Experience with the General Practice Research Database (GPRD) indicated the possibility of generating such data. The example developed concerns the probability of recurrent stroke and the risks and benefits of treatment with aspirin. Eight criteria were systematically applied to identify suitable patients from the 664,241 cohort of patients in the West Midlands GPRD. The risk of recurrent stroke was estimated using survival analysis, yielding multivariate hazard ratios for 960 patient profiles. These were used to populate a decision analysis model. The study highlights how decision analysis can introduce evidence-based information into the consultation. Data can be transformed into information for the increasingly complex world of general practice. This can clarify the risks and benefits of prescribing, assist GP—patient dialogue and promote shared decision-making.

Incidence of psychoses among drug dependent patients in primary care with no psychiatric history: a retrospective observational matched-cohort study

Background and Objectives: While several studies have indicated a link between illicit drug use and the development of psychosis, the confounding role of pre-existing psychiatric illness is unclear. This study controls for this factor to a greater extent than has hitherto been possible, using a retrospective observational matched-cohort design controlling for age, gender, socioeconomic status and prior psychiatric illness. Methods: 592 cases (diagnosed with drug misuse/dependence) and 592 controls (no recorded history of drug misuse/dependence) were drawn from all patients aged 16-44 in 183 practices within the General Practice Research Database (UK). On study entry, cases and controls had never had a psychiatric diagnosis since registering with their practice. The average look-back period was 17.7 years. The main outcome measure was diagnosis of psychosis (including schizophrenia) from study entry onwards. Results: Patients with a drug misuse/dependence diagnosis are significantly more likely to be diagnosed with psychosis than those with no drug misuse/dependence history (RR = 2.10, 95% C.I. = 1.23-3.59) with the relative risk increasing as the definition of psychosis gets narrower. Conclusions: This study has established that, when the confounding presence of previous psychiatric illness is removed, the onset of problematic substance misuse severe enough to warrant primary care consultation is a risk factor for future onset of first-ever psychotic illness. Thus, there is a distinct sub-group of psychotic patients among whom drug misuse/dependence, with no prior psychiatric illness, is a risk factor for the development of psychoses.