The Waikato Medical Care (WaiMedCa) Survey 1991-1992
McAvoy, B.; Davis, P.; Raymont, A.; Gribben, B.
New Zealand Medical Journal 107(986 Pt 2): 388-433
1994
ISSN/ISBN: 0028-8446 PMID: 7936474 Document Number: 433584
Objective: The main objective of this study is to provide a comprehensive description of general practice in the Waikato, an area which represents many aspects of New Zealand. Accurate, detailed and up to date information in this area is needed for future planning of medical education and the provision of health services. Survey method: The survey was conducted over one year, from September 1991 to August 1992. Participating general practitioners and practice nurses recorded details of a sample of patient encounters in the surgery or on home visits. Each participant was assigned four single weeks for data gathering over the course of the year. A one in five sub-sample of patients was also given questionnaires to complete immediately and two weeks after the consultations. This component of the study was reported elsewhere. Participants: A list of all active general practitioners working within the area covered by the Waikato Area Health board was constructed. All were contacted during May and June 1991 and asked to contribute to the study. During this initial, recruiting stage the practitioners and their practice nurses were asked to provide details of their professional background and to outline the structure, functions and size of their practices. Data collection: The variables studied included: provider characteristics (age, gender, qualifications, type of practice and services offered); patient attributes (age, gender, ethnicity, benefit category and occupation); patient reasons for encounter (up to four per encounter); doctor diagnoses (again up to four per encounter); drugs prescribed and or other treatments provided; tests and investigations ordered and referrals made; planned follow up and subjective view on the encounter. Data were centrally coded by trained staff. Patient reasons for encounter were coded according to NAMCS, practitioner diagnoses were classified into OXMIS, and drugs prescribed were allocated into the ATC classification system. Participation rate. 87% of practitioners (182/209), 89% of practices (95/107), and 80% of practice nurses (150/189) completed the initial recruitment survey. The participation rate at the first phase of the encounter survey was 80.5% (169/210), but this had dropped to 65.7% (136/207) by the fourth collection week. An overall response rate of 68.6% was achieved, representing successful collection of encounter data in 562 of 819 potential doctor recording weeks. On average, general practitioners recorded 109 encounters per week, from which they selected on average a sample of 23 patients for the survey. They described 141 problems per 100 encounters, of which 49 were new. On average general practitioners made less than three home visits per 100 encounters. Patient encounters: In all, 12 833 encounters were recorded. After excluding patients attending accident and emergency clinics, a final sample of 11,888 remained. New patients accounted for 7.4% of visits. There were more female patients (57.8%), and the very young and those in the retirement years were represented at a level above that of the population. Active follow up was recommended in 40% of encounters. Reasons for encounter: Patients gave a total of 16,398 reasons for encounter (RFEs), a rate of 138 per 100 encounters. At 69.3% of visits, a single reason was given. The most frequent reasons related to respiratory symptoms, followed by a request for therapy, and musculoskeletal, skin, general/nonspecific, and digestive symptoms. The commonest individual RFEs were request for a prescription (8.5 per 100 encounters), cough (6.8%), check-up (5.6%), throat complaint (4.7%), natal check (4.7%), rash (3.8%), and upper respiratory tract infection (3.3%). The great majority of RFEs-57.3%-were expressed as symptoms. Morbidity and treatment: Practitioners identified 16,760 problems, giving an overall rate of 141 problems per 100 encounters. In 67.6% of cases only a single problem was presented. More problems were managed in encounters with women and patients in the older age groups. Respiratory problems were most frequent (21.7% of encounters), followed by musculoskeletal (17.4%), skin (15.1%), general (12.4%) and cardiovascular (11.2%). The commonest individual problem was hypertension (6.0 per 100 encounters), followed by upper respiratory tract infection (5.5%), acute bronchitis (5.4%), natal care (5.2%), asthma (4.5%), otitis media (4.9%) and tonsillitis (3.9%). These seven conditions accounted for a quarter of all problems managed. Prescriptions. A script was issued at 7,050 encounters, representing an overall rate of 59.3 prescriptions per 100 encounters. Other kinds of treatment were recorded at 5,457 encounters (45.9 per 100 encounters). The most frequently prescribed drug groups were antibiotics (23.5% of all scripts), cardiovascular drugs (13.0%), respiratory medications (11.5%), and skin preparations (10.1%). The single most frequently prescribed drug was Augmentin (5.8% of scripts), followed by Amoxi l (4.6%), Ventolin (2.3%) and Ceclor (2.0%). In the period since the earlier Waikato general practice survey of 1979-80 there has been a decline in the rate of prescribing from 62.4 encounters per 100 to 59.3 in 1991-2. There has also been a change in the pattern of predominant drug groups being prescribed. Referrals. There were 1,211 referrals, representing a rate of 9.4 per 100 encounters. These were distributed in approximately equal proportions between the public hospital (32.7 per 100 referrals), medical specialist (33.8) and other health professionals (33.5). Just under 1% of encounters resulted in an admission to hospital. Tests. A total of 4,847 tests were ordered, a rate of 16.9 per 100 encounters. Pathology tests were most common (13.2 per 100 encounters), followed by x-rays (5.2 per 100). Nurses. Information was collected from 1,329 nurse encounters. The commonest single reasons for seeing a nurse was for immunization (17.7% of all problems), followed by blood pressure