BACKGROUND: H2-receptor antagonists and proton pump inhibitors account for approximately 15% of primary care prescribing costs in the UK. AIM: To examine the use of antisecretory drugs in primary care between October 1991 and September 1996. METHOD: Analysis of prescribing data from an ongoing postal survey performed every 3 months on a rolling quota of 250 UK general practitioners (GPs), identified from a representative sampling frame of 1000 GPs. RESULTS: There were 8811 new courses of proton pump inhibitors and 11,948 new courses of H2-receptor antagonists during this study. The number of new prescriptions for proton pump inhibitors increased by 174.5%, but decreased for H2-receptor antagonists by 12.5%. Proton pump inhibitors were mostly prescribed for reflux disease (52.7%) and H2-receptor antagonists for non-specific dyspepsia (43.6%). Proton pump inhibitors (14.1%) were less likely to be stopped than H2-receptor antagonists (35.3%) overall, and they were less likely to be stopped because of perceived ineffectiveness (5.3%) than H2-receptor antagonists (23.8%). The rate of stopping treatment because of side-effects was about 3% for both classes of drug. CONCLUSIONS: Prescribing of proton pump inhibitors has increased sharply each year since 1991. One reason may be that GPs perceive proton pump inhibitors to be more effective than H2-receptor antagonists.

Anti-Ulcer Agents↗

PubMed1998

Trials which randomize practices I: how should they be analysed?

BACKGROUND: In some general practice intervention trials, patients must be randomized in practices rather than individually, and this must be taken into account in the analysis. OBJECTIVES: In this article we aim to show how failure to do this may lead to spurious statistical significance and CIs which are narrower than they should be, and to describe the use of summary measures for each practice as a simple method of analysis. METHOD: The statistical issues are demonstrated by an example of a trial in general practice. DISCUSSION: The choice of unit of analysis will be most important where there are large numbers of patients recruited from each practice or a high degree of variability between practices.

Family Practice↗

PubMed1998

Trials which randomize practices II: sample size.

BACKGROUND: When practices are randomized in a trial and observations are made on the patients to assess the relative effectiveness of the different interventions, sample size calculations need to estimate the number of practices required, not just the total number of patients. OBJECTIVE: Our aims were to introduce the methodology for appropriate sample size calculation and discuss the implications for power. METHOD: A worked example from general practice is used. DISCUSSION: Designs which randomize practices are less powerful than designs which randomize patients to intervention groups, particularly where a large number of patients is recruited from each practice. Studies which randomize few practices should be avoided if possible, as the loss of power is considerable and simple randomization may not ensure comparability of intervention groups.

Family Practice↗

PubMed1998

Emergency nurse practitioner services in major accident and emergency departments: a United Kingdom postal survey.

OBJECTIVE: To establish the current and predicted distribution of formal emergency nurse practitioner services in major accident and emergency departments in the United Kingdom; to determine organisational variations in service provision, with specific reference to funding, role configuration, training, and scope of clinical activity. METHODS: Postal survey of senior nurses of all major accident and emergency departments in the United Kingdom (n = 293) in May/June 1996. RESULTS: There were 274 replies (94% response rate): 98 departments (36%) provided a formal service; a further 91 departments (33%) reported definite plans to introduce a service by the end of 1996; smaller departments, under 40000 new patient attendances annually, were less likely to provide a service than busier units (p < 0.001, chi2 for trend). Three different methods of making the role operational were identified: dedicated, integrated, and rotational. Only 16 (18%) were able to provide a 24 hour service; 91 departments (93%) employed emergency nurse practitioners who had received specific training, but wide variations in length, content, and academic level were noted; 82 departments (84%) authorised nurse practitioners to order x rays independently, but only 35 (36%) allowed them to interpret radiographs; 67 (68%) permitted "over the counter" drug supplying under local protocol, and 52 (54%), "prescription only" drug supplying from an agreed list. CONCLUSIONS: Formal emergency nurse practitioner services are provided in all parts of the United Kingdom, with predicted figures suggesting a rapidly accelerating upward trend. Wide variations in service organisation, training, and scope of activity are evident.

Chi-Square Distribution↗

PubMed1997

Statistics notes. Trials randomised in clusters.

Explore the source record for details and available documents.

Cluster Analysis↗

PubMed1997

General practitioners' perceptions of the tolerability of antidepressant drugs: a comparison of selective serotonin reuptake inhibitors and tricyclic antidepressants.

OBJECTIVE: To examine inceptions and discontinuations of antidepressants in general practice. DESIGN: An observational study analysing data from an ongoing cross sectional postal survey. Every three months a representative sample of 250 doctors recorded prescribing activity for four weeks. This provided 4000 general practitioner weeks of recording per year. SETTING: A representative panel of general practitioners in England, Wales, and Scotland. SUBJECTS: Patients who began a new course of an antidepressant or had their treatment stopped or changed by the general practitioner between 1 July 1990 and 30 June 1995. MAIN OUTCOME MEASURES: Numbers of patients prescribed a new course of antidepressant; numbers discontinuing treatment; the ratio of antidepressant discontinuations to antidepressant inceptions; reasons for discontinuation; proportion of switches to another antidepressant. RESULTS: There were 13,619 inceptions and 3934 discontinuations of selective serotonin reuptake inhibitors and tricyclic antidepressants during the study. The number of newly prescribed courses of antidepressants increased by 116%, mostly due to an increase in prescribing of serotonin reuptake inhibitors. The ratio of total discontinuations to inceptions was significantly lower for serotonin reuptake inhibitors (22%) than for tricyclic antidepressants (33%). Differences persisted when controlled for age and sex of patients and severity of depression. However, there was more switching away from selective serotonin reuptake inhibitors when they failed (72%) than from tricyclic antidepressants (58%). CONCLUSIONS: Selective serotonin reuptake inhibitors are less likely than tricyclic antidepressants to be discontinued. A prospective study is needed in general practice to assess the implications of differences in discontinuation rates and switches on clinical and economic outcomes.

Antidepressive Agents, Tricyclic↗

PubMed1997

The impact of the October 1995 'pill scare' on oral contraceptive use in the United Kingdom: analysis of a general practice automated database.

OBJECTIVES: We aimed to measure the change in prescribing of oral contraceptives after the October 1995 UK 'pill-scare'. DESIGN: Analysis was undertaken of an automated database of 100 general practices (372 doctors) in England, Scotland and Wales which use the AAH Meditel computer system. Analysis involved two stages. First, we reviewed prescribing of oral contraceptives at three time periods: before the scare (18.10.95); the following three months (19.10.95-18.1.96); and 3-6 months post-scare (19.1.96-18.4.96). Second, we examined the cohort of women on the pill at the time of the scare to assess discontinuation rates and pill switches after 6 months. RESULTS: Six months after the scare the proportion of women between 16 and 50 years of age prescribed any contraceptive pill decreased by only 3.5% (95% confidence limits: 2.2%-4.8%). The proportion of pill-users prescribed third generation pills decreased from 53.4% to 18.1%, while prescribing of second generation pills increased from 20.1% to 48.4%. The proportion of women currently on third or second generation pills at the time of the scare, who were no longer prescribed any pill after 6 months, was the same as for the equivalent period in the previous year. CONCLUSIONS: The number of women prescribed the pill did not alter markedly after the pill-scare. The main change was a switch from third to second generation pill types. In any future pill-scare women should be warned about the risk of pill-failure if the correct procedure for switching pills is not followed.

Adolescent↗

PubMed1994

Randomized controlled trial of the effect of the Royal College of Radiologists' guidelines on general practitioners' referrals for radiographic examination.

BACKGROUND: The Royal College of Radiologists' guidelines aim to encourage more appropriate use of diagnostic radiology and so reduce the use of clinically unhelpful x-ray examinations. AIM: The object of this study was to conduct a randomized controlled trial of the introduction of the guidelines into general practice. METHOD: A total of 62 practices (170 general practitioners) referring patients to St George's Hospital, London for diagnostic radiology were randomly allocated into two groups. Guidelines were sent to the 30 practices in the intervention group. Radiological referral patterns were compared in both groups before and after the introduction of guidelines. RESULTS: Practices which had received guidelines requested significantly fewer examinations of the spine, and made a significantly higher proportion of requests which conformed to the guidelines compared with practices which had not received the guidelines. There were no significant differences in the proportion of forms giving physical findings or in the proportion of positive findings at radiology. CONCLUSION: Introduction of guidelines can influence general practitioners' radiological referrals in the short term. Wider use of guidelines might help to reduce unnecessary irradiation of patients.

Adolescent↗

PubMed1991

Platelet alpha 2-adrenoceptors, defined with agonist and antagonist ligands, in depressed patients, prior to and following treatment.

Saturation binding of the alpha 2-adrenoceptor antagonist, 3H-yohimbine, and displacement of 3H-yohimbine with the alpha 2-adrenoceptor agonist, UK-14,304, were performed concurrently in platelet membranes obtained from drug-free depressed patients and healthy volunteers. Where possible platelet binding was repeated in depressed patients following treatment. The number and affinity of 3H-yohimbine binding sites did not differ between controls and depressed patients, or when depressed patients were divided on the basis of endogenicity (Newcastle or RDC criteria) or dexamethasone test result. The proportion of alpha 2-adrenoceptor binding sites with high affinity for UK-14,304 and KD values for the two states of the receptor did not differ in the total sample of depressed patients compared to controls. The KD for both states of the receptor and the proportion of sites with high affinity for UK-14,304 was lower in RDC non-endogenous patients than RDC endogenous patients. Treatment did not alter the total number of alpha 2-adrenoceptors or the proportion of sites with high affinity for UK-14,304, but reduced the KD for 3H-yohimbine and the KD of UK-14,304 for the low affinity state of the alpha 2-adrenoceptor.

Adrenergic alpha-Agonists↗

PubMed1990

3H-imipramine binding to previously frozen platelet membranes from depressed patients, before and after treatment.

3H-imipramine binding in 39 drug-free patients with major depression and 44 healthy controls did not differ significantly between the two groups, in male or female subjects or in subgroups of depressed patients divided by endogenicity or dexamethasone suppression test result. 3H-imipramine binding in depressed patients drug-free for less than three weeks did not differ from those drug-free for longer intervals or from controls. A significant seasonal variation of 3H-imipramine Bmax was found, with lower values in summer and autumn. Treatment of depressed patients with imipramine or lofepramine for six weeks increased KD and Bmax. Methodological modification (in preparation and storage of platelets) does not explain the major differences in results between this study (using frozen platelets), a previous one (using freshly prepared platelets) and others in general, although it might contribute to the range of values reported.

Adult↗

PubMed1989

3H-imipramine binding to freshly prepared platelet membranes in depression.

3H-Imipramine binding was measured in freshly prepared platelet membranes from 47 drug-free major depressives and 46 healthy controls. Where possible, platelet binding in depressed subjects was repeated following treatment. A significant negative correlation was found between Bmax and assay protein concentration and Bmax values were corrected for this effect. Adjusted Bmax was significantly lower (by 14%) in female depressed patients than in female control subjects, and the difference was of similar magnitude premenopausally and postmenopausally. No such difference was found in males. Kd did not differ significantly between depressed and control subjects. Multiple regression analysis confirmed significant effects on Bmax of presence of depressive illness, age (positive correlation), and season (higher in summer). Within the depressed sample, Bmax was significantly lower in those subjects with obsessional features. Endogenicity (Research Diagnostic Criteria or Newcastle), dexamethasone suppression test result, drug-free interval, family history of depression, depressive psychosis, suicidal ideation, and past history of suicide attempts were not significantly related to Bmax. Paired comparisons revealed no significant effect on Bmax of 6 weeks' treatment with imipramine, maprotiline, or BRL 14342 or of a course of electroconvulsive therapy.

Adult↗

PubMedDate not supplied

[3H]yohimbine binding to platelet alpha 2-adrenoceptors in depression.

[3H]Yohimbine binding to platelet alpha 2-adrenoceptors was studied in depressed patients and healthy volunteers. Where possible platelet binding measurement was repeated in depressed patients following treatment. Bmax of [3H]yohimbine binding did not differ significantly between depressed patients and control subjects and did not change with treatment in depressed patients. KD was significantly lower in female depressed patients, particularly in those who were post-menopausal. Multivariate analysis showed significant effects on KD of depression, season of testing and assay protein concentration.

Adult↗