Chapter 3 Prevalence and G P Utilisation Studies in Older
3.6 Method— b) General Practitioner Encounters
3.6.1 Design
A survey o f all GP encounters (surgery and home) for two one-week periods (six months apart) from October 1990 to October 1991 was conducted by the Family Medicine Research Unit o f the University o f Sydney (Bridges-Webb, Britt, Miles, Neary, Charles, & Traynor, 1992).
3.6.2 Sample and Setting
From a prelisting o f GPs (practitioners who provided > 1,500 Medicare items o f service in 1989) a stratified random sample o f 495 GPs participated (50.4% o f the available practitioners) in the Survey o f Morbidity and Treatment in General Practice in Australia (Bridges-Webb et al., 1992). This sample, representing 3.5% o f practitioners in all states or territories, was weighted so that a minimum o f 20 GPs or 4,000 encounters from each state were represented (Bridges-Webb et al., 1992). These final data were again weighted to produce a balanced national sample o f GP encounters (Bridges-Webb et al., 1992).
3.6.3 Instruments
At each encounter, a recording form (Appendix A) requested information on: the date o f the encounter, item o f service, patient age and sex, patient status (new/old patient to practice), patient reasons for encounter (why he or she came to the surgery; up to three), problems /diagnoses (highest diagnostic level or in terms o f disease, symptom and ill-defined condition, a psychological or social problem or service; up to four), new/old problem to patient, drugs prescribed/other treatments given (up to four per problem), tests, investigations (up to 14), inpatient hospital or nursing home admissions, referrals (up to two), and follow-up planned within three months for any o f these problems (Bridges-Webb, 1992). All problems/diagnoses were subsequently coded using the International Classification o f Primary Care (ICPC), 1990. Accuracy o f the coding o f individual problems was reported as a 2% error rate by Bridges-Webb et al. (1992). Inter-rater reliability and the mean intra-rater reliability for problems was reported as 86.9% agreement and 90.3%, respectively (Bridges-Webb et al., 1992). Under this classification system, ‘S97’ refers to the following diagnoses/problems: Bedsore, Pressure sore, Decubitus Ulcer, and Skin Ulcer or Varicose ulcer. Only those diagnoses/problems that were leg ulcers were included.
3.7
Results
Tabulations o f these data from the Survey o f Morbidity and Treatment in General Practice in Australia (Bridges-Webb et al., 1992) were performed by the Family Medicine Research Unit (FMRU) o f the University o f Sydney for this investigator. Descriptive statistics on the various codings— age, sex, health problems o f patients, and
therapies— were provided. All encounters (unweighted) were then coded by the investigator into type o f ulcer based upon the description given by the GP. The resultant leg ulcer groupings were: venous, aetiology undefined, traumatic, foot or toe, and arterial or ischaemic.
A total o f 791 encounters across all ages (0.5% o f all problems 145,798.57) included S97 as one o f the problems during an encounter. Two percent o f encounters were confirmed as miscodings, and an additional 47 (6%) encounters could not be located. From the 645 confirmed encounters for leg ulcers, representing 82% o f the S97 category, 69% o f patients were female. Eighty-five percent (/? = 548) o f encounters for leg ulcers were in the 60 years or more age group. The highest frequency o f encounters for leg ulcers was seen in the age group 75-79 years (22%) (Figure 1, page 19). Figure 1 demonstrates the concentration o f sufferers in the age ranges 70-84.
A comparison was made with the most frequently occurring encounter problems in patients 60 years and over (Table 5, page 20). It should be noted that there can be more than one problem for each encounter. This tabulation demonstrates that 626.39/52,430.63 (1.2%) o f encounters were for ulcer skin/bedsore; 0.98% being confirmed leg ulcers (82% o f 626.39).
<60 60-64 65-69 70-74 Age 75-79 80-84 85-89 90-94 95 + 0 20 40 60 80 100 120 140 160 Number
Figure 1: Age Distribution for All GP Encounters for S97 that were Confirmed
Leg Ulcers N = 645
Data Source: Bridges-Webb et al. (1992). Survey of Morbidity and Treatment in General Practice in Australia. The sam e person can have more than one encounter.
Table 5:
Problems in Frequency Order (60 or more years)
D iagn osis/P rob lem F req u en cy %
Uncomplicated hypertension 6,254.81 11.9
Heart failure 1,525.66 2.9
Other osteoarthritis excluding spine, hip, knee and shoulder 1,339.57 2.6
Diabetes mellitus 1,306.16 2.5
Other and chronic ischaemic heart disease 1,119.87 2.1
Disturbances of sleep/insomnia 1,058.72 2.0
Acute bronchitis/bronchiolitis 1,030.65 2.0
Emphysema/chronic pulmonary disease 997.51 1.9
Anxiety disorder/anxiety state 929.41 1.8
Upper Respiratory Infection head cold/rhinitis NOS 890.87 1.7
Lipid metabolism disorder 859.27 1.6
Asthma 856.61 1.6
Symptoms/complaints of skin texture 814.95 1.6
Depressive disorder/anxiety/depression 799.57 1.5
Diagnostic/preventive procedures 776.3 1.5
Malignant neoplasms of skin 656.41 1.3
Cystitis/other urinary infections non-venereal 644.96 1.2
Ulcer Skin/Bedsore (inc. Varicose Ulcer)1 626.39 1.2
Contact dermatitis/skin allergy 618.61 1.2
Angina pectoris 595.08 1.1
Osteoarthritis of spine 586.58 1.1
Other disease musculoskeletal system 467.4 0.9
Symptom./complaint multiple joints arthritis N.O.S. Arthralgia 464.68 0.9
Arthritis of the knee 421.05 0.8
Diagnostic/preventive procedures 415.34 0.8
Gout 404.78 0.8
Lumbar disc lesion, back pain with radiating symptoms 401.15 0.8
Ear wax excessive 384.35 0.7
Osteoporosis 373.62 0.7
Other arterial obstruction/peripheral vascular disease/gangrene/limb ischaemia
350.41 0.7
Rheumatoid arthritis and allied conditions 347.75 0.7
Dementia 343.9 0.7
Weighted data has been used in these analyses. N.O.S. Not otherwise specified.
For the 60 years and over group total problems/diagnoses equals 52,430.
Total number of problems across all ages was 145,799 and total number of encounters was 98,796. List truncated at 0.6%.
Data Source: Bridges-Webb et al. (1992). Survey of Morbidity and Treatment in General Practice in Australia.
The various types o f leg ulcers are given in Table 6. It should be noted that these data are based on encounters and not individuals— an individual may appear more than once— although data is collected at two one week periods six months apart, making the opportunity for this, small.
Table 6:
Leg Ulcer Type Distribution in sample >60 years of age
Type Frequency %
Venous ulcer 227 37.8
Leg ulcer (undefined aetiology) 225 37.5
Traumatic ulcer 65 10.8
Foot or toe ulcer 35 5.8
Arterial/Ischaemic ulcer 48 8.0
Total 600 100.0
This analysis was performed on unweighted data.
Data Source: Bridges-Webb et al. (1992). Survey o f Morbidity and Treatment in General Practice in Australia.
A mixture o f types o f ulcers appeared in these data. Some general practitioners described the ulcer by the site; for example, toe, foot or leg. Others described the ulcer by the terms varicose or venous, arterial or ischaemic. The large proportion o f leg ulcers in the ‘traum a’ group was unexpected (10.8%). Ulcers may occur spontaneously or from trauma. Venous and arterial disease may also be present when trauma occurs. From Table 6, 37.8% were described as venous and 14% (foot or toe ulcers and arterial/ischaemic group) could possibly be considered as arterial. A large proportion o f leg ulcers were not classified into any particular group (37.5%). This could reflect an unidentified distribution o f both venous and arterial disease or alternatively demonstrate that the precise aetiology was irrelevant to the practitioner. These codings are based on the stated diagnoses or problems given by the general practitioner.
Further tabulation o f the co-existence o f diseases in these groups was undertaken. The other problems managed at encounters for leg ulcers (includes all ages) at a percentage frequency o f 3% or more were hypertension, diabetes, heart failure, and osteoarthritis. Peripheral vascular disease was also noted in 2.4% o f encounters for S97 (Table 7, page 22).
Table 7:
Frequency Distribution of Other Health Problems at Encounters for
Leg Ulcers
Problem F req u en cy % Hypertension 46.33 12.0 Diabetes 30.82 8.0 Heart Failure 27.51 7.1 Osteoarthritis 13.10 3.4 Arthritis 12.46 3.2Acute Myocardial Infarction 10.56 2.7
Peripheral Vascular Disease 9.46 2.4
Emphysema/Chronic Obstructive Pulmonary Disease 9.23 2.4
Insomnia 8.57 2.2
Bronchitis Acute 7.69 2.0
This table uses Grouped ICPC Codes and is based on problems not encounters. Table truncated. Total number o f problems was 387.6.
Data Source: Bridges-Webb et al. (1992). Survey o f Morbidity and Treatment in General Practice in Australia.
The types o f treatments prescribed are discussed under the two major groupings o f prescriptions (broad drug type) and treatments provided. Antibiotics and skin preparations represented 75% o f all prescribed drugs for the leg ulcer group. Diuretics were ordered infrequently (0.6% [1.94 frequency]). Treatments provided by the GPs were mainly in the bandage/dressing (eg. clean wound) category (84% [376.57 frequency]). Advice formed the other area o f treatment (4% [20.79 frequency]). Referrals from the general practitioner were mainly to home nursing (38.7% o f encounters), surgeons (22.9%), and dermatologists (13.6%). The GPs made home visits in 12% o f leg ulcer encounters, three times the average for other problems
3.8
Discussion
These results demonstrate that skin ulcers account for 1.2% o f encounters in patients over the age o f 60 years and 0.5% across all ages; confirmed leg ulcers being approximately 0.98% in the over 60 years. The age distribution for the encounters was consistent with previous research in the area with a median age o f 75 years (median 74 years for women and 69 years for men) (Callam et al., 1987; Nelzen et al., 1991; Baker et al., 1991). Unlike other studies, the peak frequency was observed in the 75-79 year old group. At older ages the frequency begins to decline, perhaps reflecting the decreasing population proportions in those ages, or decreasing abilities in these groups to attend GP practices. Similar to Nelzen et al.’s study, 85% o f all encounters for leg ulcers were in the 60 years or more group. Caution in interpretation is recommended as these are
encounters, not first encounters for the condition. Multiple encounters for the same individual are possible, but would not be a frequent occurrence in this dataset, which is based on only 2 recording weeks (six months apart) for each GP.
The gender distribution in this study was also similar to the study by Nelzen et al. (1991) with 69% female. Conditions that co-existed in these patients were consistent with the literature (hypertension, diabetes, heart disease, peripheral vascular disease, and osteoarthritis). The contribution o f leg ulcers to general practitioner encounters suggests a considerable cost burden to health services. In terms o f the impact this problem has on mobility in older people, it would seem to be the single most frequently encountered condition surpassing encounters for osteoarthritis for the knee or spine as separate categories. Treatments given by general practitioners were consistent with those promoted in the literature, with the exception o f the low prescription rate o f diuretics, which remains controversial. The high rate o f referral to home nursing was consistent with the high utilisation o f community nursing services reported in the literature.