The link between major risk factors and important categories of admission in an ageing cohort.

BACKGROUND: Record linkage of routine hospital data to population-based research findings presents an opportunity to explore the relationships between classical risk factors and hospital activity. METHODS: The objectives of this study were to examine, in Paisley and Renfrew, the effect of risk factor variables on the likelihood of experiencing an acute hospital admission with six major medical conditions. The subjects were 8,349 women and 7,057 men, aged 45-64 in the early to mid-1970s. The main outcome measures were acute hospital admission with principal diagnosis of: any malignant neoplasm; malignant neoplasm of trachea, bronchus and lung; ischaemic heart disease; respiratory disease; cerebrovascular disease; or diabetes mellitus. RESULTS: Smokers were almost eight times more likely to be admitted with lung cancer and, to a lesser extent, were more likely to be admitted for the other conditions investigated with the exception of diabetes mellitus. Forced expiratory volume was also an independent risk factor for admission with lung cancer and strokes. Higher levels of cholesterol were associated with increased risk of admission with ischaemic heart disease but less with cancer (including lung cancer). With the exception of admissions for cerebrovascular disease, deprivation category was found to have no independent effect on the likelihood of experiencing any of the morbidity outcomes examined. CONCLUSIONS: These data confirm that associations first established between risk factors and mortality outcomes (e.g. smoking and lung cancer) are also found between risk factors and hospital admissions for the same causes. This in itself is unremarkable, but the results are of interest for three reasons. First, they illustrate the potential of record linkage to map the effects of risk factors. Second, they demonstrate the size of the effect risk factors have on the risk of admission. Third, they provide a surprising finding that deprivation category does not act as an independent risk factor for the majority of the categories of admission investigated.

Influence of biological, behavioural, health service and social risk factors on the trend towards more frequent.

OBJECTIVES: To analyse the trend in rising acute hospital admission rates in the Renfrew Paisley MIDSPAN cohort and assess the influence of baseline risk factor data, morbidity patterns, deprivation category and characteristics of GP practice on the increase. DESIGN: Cohort analysis which, using a linked data set covering a 23 year follow-up period, combined original 'risk'-related data with subsequent routine hospital admissions data. A multiple logistic regression model predicted changes in hospital admissions patterns. SETTING: Renfrew and Paisley, two post-industrial towns in Scotland. SUBJECTS: Eight thousand three hundred and fifty four women and 7,052 men, aged 45-64 in the early 1970s. MAIN OUTCOME MEASURES: The contribution that each of the factors investigated made to the likelihood of admission over time. RESULTS: While risk status in middle life, diagnosis reached after admission, deprivation category and characteristics of GP practice influence the absolute chance of being admitted to hospital, changes in these factors do not explain much, if any, of the quite marked increase in admission rates observed during the last 10 year of the follow-up period. CONCLUSIONS: Whatever the reasons for the trend of rising admission, the most likely explanation appears to be a combination of social and health service related factors. For the Paisley-Renfrew cohort, factors like smoking status, FEV1, deprivation category and GP practice remain important predictors of admission throughout the time period but changes in these factors explain little of the rising trend in admissions.

Hospital use by an ageing cohort: an investigation into the association between biological, behavioural and social risk markers and subsequent hospital utilization.

BACKGROUND: The aims of the study were to describe the pattern of hospital utilization (acute and mental health sectors) of the Paisley-Renfrew MIDSPAN cohort and assess the influence of biological, behavioural and social 'risk factors' (established at the time of screening) on subsequent hospital admissions. METHOD: A cohort analysis was carried out in Paisley and Renfrew, two post-industrial towns in West Central Scotland. This used a linked data set covering a 23 year follow-up period to combine original 'risk'-related data with subsequent routine hospital admissions data. The subjects were 8349 women and 7057 men, aged 45-64 in the early to mid-1970s, and representing approximately 80 per cent of the eligible population. The main outcome measures were patterns of hospital utilization (acute and mental health sectors), 'any acute hospital admission', 'a serious acute hospital admission' and 'death' (relative risks of each outcome were calculated for all risk factors). RESULTS: The following patterns of hospital utilization were found. Only 5 per cent experienced a mental health admission but mean stay was long (265 bed days per cohort member admitted). In contrast, 79 per cent experienced at least one acute hospital stay. The age-specific proportions of cohort members requiring admission increased over time but the growth in acute episodes was even higher (suggesting increasing rates of multiple admission). For non-survivors, 42 per cent of all acute episodes (55 per cent of bed days) took place during the 12 months before death. Analysis of risk factors (using Cox's proportional hazards model) of 'any admission' and 'a serious admission' showed forced expiratory volume (FEV1), age, sex, smoking status, blood pressure, blood sugar, body mass index, cholesterol and deprivation category to be important predictors. CONCLUSIONS: Despite the desirability of alternative settings of care for the chronically ill and dying, a high proportion of hospital bed days were required near the time of death. The absolute size of the demand for hospital services within the cohort was strikingly large and increasing over time. Strategies to address the tide of rising admissions will have to confront the increasing proportion of individuals requiring admission as well as the growth in multiple admissions. Those who were at higher risk of admission were the older members of the cohort (especially men), those with low FEV1, smokers, those who were underweight or obese, the small number with abnormal levels of blood sugar, those with high blood pressure and those who lived in the most deprived areas. Thus, programmes which affect these determinants of ill health may be useful in reducing age-specific admission rates.

Cardiac and vascular morbidity in women receiving adjuvant tamoxifen for breast cancer in a randomised trial. The Scottish Cancer Trials Breast Group.

OBJECTIVE: To determine any cardiac or vascular morbidity associated with long term treatment with tamoxifen given after mastectomy for primary breast cancer. DESIGN: Cohort study using linkage between database of a randomised trial and statistics of Scottish hospital inpatients to identify episodes of cardiac and vascular morbidity. SETTING: NHS hospitals in Scotland. SUBJECTS: 1312 women who had undergone mastectomy for breast cancer and who were randomised either to a treatment group to receive adjuvant tamoxifen or to a control group to be given tamoxifen only on first relapse of disease. Maximum duration of tamoxifen treatment was 14 years. Total woman years of follow up were 9943. MAIN OUTCOME MEASURES: Randomised and observational comparisons of risk (expressed as hazard ratios) of myocardial infarction, other cardiac event, cerebrovascular disease, or thromboembolic event according to treatment allocated and between nonusers, former users, and current users of tamoxifen. RESULTS: Use of tamoxifen was associated with lower rates of myocardial infarction. Hazard ratio for women in control group was 1.92 (95% confidence interval 0.99 to 3.73) compared with women allocated to adjuvant treatment. The association was stronger for current use: hazard ratio for non-users was 3.49 (1.52 to 8.03) compared with current users. Current users of tamoxifen, however, had higher rates of thromboembolic events:hazard ratio for non-users was 0.40 (0.18 to 0.90) compared with current users. CONCLUSIONS: Our results provide further evidence that tamoxifen reduces the risk of myocardial infarction. Thromboembolic events should be carefully monitored in trials of tamoxifen, particularly those of prophylactic treatment, in which tamoxifen is given to healthy women.