Survey on repeat prescribing for acid suppression drugs in primary care in Cornwall and the Isles of Scilly

Transcription

1 Aliment Pharmacol Ther 1999; 13: 813±817. Survey on repeat prescribing for acid suppression drugs in primary care in Cornwall and the Isles of Scilly R. BOUTET, M. WILCOCK & I. MACKENZIE 1 Department of Public Health Medicine, Cornwall and Isles of Scilly Health Authority, St Austell, Cornwall, UK Accepted for publication 5 January 1999 SUMMARY Background: Repeat prescriptions for acid suppression therapy represent an important burden on health care resources. Aim: To determine the prevalence of acid suppression therapy and its indications by general practitioners (GPs) in a larger sample of practices than previous studies. Method: Practices in Cornwall and the Isles of Scilly were invited to identify the number of patients on repeat prescription for acid suppression drugs in their practice, to review the indication for treatment in a sample of 50 patients, and to indicate the mode of review of these patients. Results: Out of 77 practices, 42 (55%) participated in the study. Overall, 5% of patients were authorized to receive a repeat prescription for acid suppression drugs. Repeat rates varied between practices, from 1.68% to 11.11%. Repeat rates increased with age and were higher in men than in women. Only 41% of patients had a proven diagnosis of gastro-oesophageal re ux disease or peptic ulcer. A review of notes was the most frequent way (36%) stated by GPs to review acid suppression therapy. Conclusion: The repeat rate found in our study was higher than that found in previous studies. A high proportion of older patients in Cornwall, as well as a continuing increase in the prescription of acid suppression drugs, may account for these results. BACKGROUND An important part of health resources are spent on prescriptions for acid suppression therapy each year in Cornwall. In 1996 the cost of prescriptions for these drugs amounted to 6.15 million [Prescription Pricing Authority. Prescription analysis and cost (PACT) data. Financial year 1996, unpublished data], which represents 14% of the total prescription cost for the district and 2% of the health authority budget. In addition there has been a continuing rise in the cost associated with acid suppression drugs, due mainly to an increasing use of proton pump inhibitors (Figure 1). This is a national trend, but it is particularly relevant in Cornwall where Correspondence to: Dr I. F. Mackenzie, Cornwall and Isles of Scilly Health Authority, John Keay House, Tregonissey Road, St Austell, Cornwall PL25 1 4NQ, UK. ian.mackenzie@ho.cios-ha.swest.nhs.uk the cost of acid suppression therapy is above the average for England. Studies have shown that a majority of acid suppression drugs are prescribed on a repeat basis and about 80% of the cost associated with these drugs is generated by repeat prescriptions; 1, 2 a repeat prescription has been de ned as a prescription issued without a consultation. 1 The nancial burden of acid suppression drugs on health resources is therefore linked to repeat prescriptions. In previous studies repeat prescription rates varied between 1% 3±5 and 4.4%, 6 but these studies were based on a small sample of practices that were not representative of all English practices. There is evidence suggesting that repeat prescriptions may lead to an inappropriate use of acid suppression drugs, in turn leading to a waste of resources and possible damage to patients' health. A recent study carried out in seven practices in Dundee 6 has shown that 44% of patients with repeat prescriptions for acid Ó 1999 Blackwell Science Ltd 813

2 814 R. BOUTET et al. Figure 1. Trends in the expenditure on acid suppression drugs in Cornwall from the nancial year 1991/92 to the nancial year 1996/97. Source: Pre- 1 scription Pricing Authority. suppression drugs did not have a con rmed diagnosis of peptic ulcer or of oesophagitis, which are the main indications for these drugs. Another study carried out in 50 general practices in Leeds 7 has shown that the majority of patients on repeat prescription are not reviewed by their general practitioner (GP). This may have serious adverse effects on patients' health, because the long-term use of proton pump inhibitors leads to gastric atrophy in some patients and can create a potential risk for gastric cancer. 8 This study was undertaken to estimate the rate of patients on repeat prescriptions for acid suppression therapy in Cornwall, and to review the indications for this therapy and the management of these patients by GPs. METHODS The study took place between March and June All 77 general practices in Cornwall and the Isles of Scilly were invited to participate in the study and offered payment for collecting the appropriate data on a form designed for the survey. Practices were asked rst to identify patients on repeat prescription for acid suppression therapy falling in the following age categories: 15±44, 45±64 and 65 years or over. No data were collected for patients under the age of 15 years; it was assumed that no patients would be on repeat prescription for acid suppression therapy under this age. Patients on repeat prescription for acid suppression therapy were de ned as patients having the authorization to request a prescription without seeing a doctor for the following drugs: cimetidine, ranitidine, nizatidine, famotidine, omeprazole, lansoprazole and pantoprazole. Practices were then asked to review the notes of 50 consecutive patients requesting a repeat prescription for acid suppression therapy and record which of the following indications had led to acid suppression treatment: proven peptic ulcer by investigation (barium meal or endoscopy), proven gastro-oesophagal re ux disease or hiatus hernia, suspected peptic ulcer or gastro-oesophagal re ux disease (no investigation), functional dyspepsia, prophylactic treatment for nonsteroidal anti-in ammatory drugs, oral corticosteroids or aspirin, other indications speci ed by GPs, or no clear indication. Practices were asked to indicate whether the GP reviewed the drugs of patients on repeat prescription for acid suppression therapy in a speci c consultation, when patients consulted for other reasons (opportunistic review), or whether the review was limited to patients notes. RESULTS Out of 77 practices, 42 (55%) participated in the study. Some differences were found between participating and non-participating practices in terms of fund-holding status (11/42 vs. 13/35), dispensing status (20/42 vs. 19/35) and training status (18/42 vs. 9/35), but none were statistically signi cant. As shown in Table 1 repeat rates increased with age and repeat rates were higher in men than in women. Assuming a nil repeat rate for patients for the ages 0±14 years, the overall rate was 5% (95% CI: 4.92±5.07) of the registered practice population (all ages). Ó 1999 Blackwell Science Ltd, Aliment Pharmacol Ther 13, 813±817

3 REPEAT SUBSCRIBING FOR ACID SUPPRESSANTS 815 Table 1. Repeat prescription rate by age group and sex per 100 population Age group (years) Males Females Signi cance of difference* 15± (1.45±1.84) 1.17 (0.97±1.36) P < ± (6.47±6.86) 6.1 (5.9±6.29) P = (14.03±14.81) (13.80±14.58) P = 0.26 *v 2 test, d.f. = 1. 95% con dence interval for repeat rates are shown in parentheses. Repeat rates varied considerably between practices, from 1.68% to 11.11% as shown in Figure 2. The indication for a repeat prescription for acid suppression therapy identi ed by practices from a sample of 2100 notes is shown in Figure 3. Nineteen practices said the annual review of patients on repeat prescription for acid suppression therapy involved a consultation with patients. This consultation was opportunistic for eight practices (19%); for 11 practices (26%) a speci c consultation was arranged with patients. Fifteen practices (36%) only reviewed the notes of patients. Eight practices (19%) did not specify the mode of review of their patients. DISCUSSION Reservations about the results relate to the accuracy of the data, which relied on repeat prescription registers kept by practices. We cannot exclude that some registers were not up-to-date and that some patients had been counted even though they may have left the practice. The assumption of a nil repeat rate for patients under the age of 15 may have led to an underestimate of the global repeat rate (5%). The major ndings of this study are that repeat prescribing of acid suppression drugs was widespread in the populations sampled, and only 41% of patients, who were authorized to receive repeat prescriptions for one of these drugs, had a proven diagnosis of gastrooesophageal re ux disease or peptic ulcer. Men had a signi cantly higher repeat prescription rate than women in the age groups 15±44 and 45±64 years. A sex difference was reported in two other studies. 9, 10 In one study, 9 which assessed acute and repeat prescription rates for acid suppression drugs, H2-receptor antagonist rates were higher in men than in women. In a second study, 10 which considered patients with new courses of acid suppression therapy, prescription rates were also higher in men than in women except for the ages 65± 84 years. Previous studies of long-term prescribing of acid suppression therapy have produced prevalence gures ranging from about 1% of the population 3±5 to 4.4%, 6 and to 5% in this study. There may be several reasons why these gures differ. First, the de nition of cases varies between studies. Ryder et al. 3 and McCullagh et al. 4 considered patients on repeat prescription for acid suppression therapy with continuous treatment for 6 months or more. Rubin Figure 2. Repeat prescription rate by practice (standardized for age and sex using Cornwall and the Isles of Scilly general practice population, with 95% con dence interval). Ó 1998 Blackwell Science Ltd, Aliment Pharmacol Ther 13, 813±817

4 816 R. BOUTET et al. Only 26% of practices stated that they formally reviewed their patients annually in a speci c consultation and 19% said they reviewed the indication of acid suppression therapy in these patients opportunistically during a consultation for another reason. A study carried out in Leeds 7 found evidence of review for 32% of patients on repeat prescription for acid suppression therapy in GPs' notes over a period of 15 months. In our study a higher proportion of practices claimed they reviewed their patients but this has not been ascertained by a review of patients notes. CONCLUSION Figure 3. Indications for treatment for patients on repeat prescription for acid suppression therapy (n ˆ 2100 patients). et al. 5 evaluated patients who had received continuous therapy (10 months' supply in the previous year) and intermittent therapy (6±10 months' supply in the previous year). In the study by Goudie et al. 6 patients had to be authorized to receive repeat prescriptions for an ulcer healing drug (which included an insigni cant number of patients on misoprostol), and to have received at least one prescription in the previous 12 months. 3 In this Cornish study we included all patients who were authorized to receive a repeat prescription for acid suppression treatment. Second, as shown in our study, repeat rates varied between practices and previous studies were based on a small number of practices. Third, Cornwall has a higher proportion of older residents than the rest of England (20% of patients were aged 65 years and over compared with 16% in the rest of England). 11 Fourth, this study was conducted quite recently whereas the other studies described are at least 3 years old and there is evidence that the volume of prescriptions for acid suppression drugs has steadily increased. 12±14 In the present study, 41% of patients who were authorized to receive repeat prescriptions for acidsuppression drugs had a diagnosis of peptic ulcer or gastro-oesophageal re ux disease con rmed by investigation. This compares with gures of 56% 3 and 60% 6 in other studies. Cornwall has access rates for endoscopy below the national average and this may be material. The higher repeat rates for acid suppression therapy found in our study seems to be consistent with the considerable and increasing amount of resources spent on acid suppression therapy. Our study, in keeping with other studies, suggests that the method of review of patients on repeat prescription is not systematic. ACKNOWLEDGEMENT We thank all the Cornish practices that participated in 1 the survey. REFERENCES 1 National Audit Of ce. Repeat Prescribing by General Practitioners in England. London: HMSO, Harris CM, Dajda R. The scale of repeat prescribing. Br J Gen Pract 1996; 46: 649±53. 3 Ryder SD, O'Reilly S, Miller RJ, Ross J, Jacyna MR, Levi AJ. Long term acid suppressing treatment in general practice. Br Med J 1994; 308: 827±30. 4 McCullagh M, Brown C, Bell D, Powell K. Long term acid 1 suppressing treatment. Br Med J 1994; 308: Rubin GP, Contractor B, Bramble MG. The use of long-term acid-suppression therapy. Br J Clin Pharmacol 1995; 49: 119±20. 6 Goudie BM, McKenzie PE, Cipriano J, Grif n EM, Murray FE. Repeat prescribing of acid suppression drugs in general practiceðprevalence and underlying diagnosis. Aliment Pharmacol Ther 1996; 10: 147±50. 7 Zermansky AG. Who controls repeats? Br J Gen Pract 1996; 46: 643±7. 8 Kuipers EJ, Lundell L, Klinkenberg EC, et al. Atrophic gastritis and Helicobacter pylori infection in patients with re ux oesophagitis treated with omeprazole or fundoplication. N Engl J Med 1996; 16: 1018±22. 9 Roberts SJ, Bateman DN. Prescribing of antacids and ulcerhealing drugs in primary care in the north of England. Aliment Pharmacol Ther 1995; 9: 137±43. Ó 1999 Blackwell Science Ltd, Aliment Pharmacol Ther 13, 813±817

5 REPEAT SUBSCRIBING FOR ACID SUPPRESSANTS Martin RM, Lim AG, Kerry SM, Hilton SR. Trends in prescribing H2-receptor antagonists and proton pump inhibitors in primary care. Aliment Pharmacol Ther 1998; 12: 797± Department of Public Health. Annual report. St Austell: Cornwall and Isles of Scilly Health Authority, Department of Health. Statistics of Prescriptions Dispensed in the Family Health Services Authorities: England 1985±95. London: Department of Health, (Statistical bulletin 1996/17.) 113 Department of Health. Statistics of Prescriptions Dispensed in the Community: England 1986±96. London: Department of Health, (Statistical bulletin 1997/15.) 14 Bashford JNR, Norwood J, Chapman SR. Why are patients prescribed proton pump inhibitors? Retrospective analysis of link between morbidity and prescribing in the General practice Research Database. Br Med J 1998; 317: 452±6. Ó 1998 Blackwell Science Ltd, Aliment Pharmacol Ther 13, 813±817