Seasonal congestive heart failure mortality and hospitalisation trends, Quebec 1990-1998.

STUDY OBJECTIVE: To describe seasonal congestive heart failure (CHF) mortality and hospitalisations in Quebec, Canada between 1990-1998 and compare trends in CHF mortality and morbidity with those in France. DESIGN: Population cohort study. SETTING: Province of Quebec, Canada. PATIENTS: Mortality data were obtained from the Quebec Death Certificate Registry and hospitalisation from the Quebec Med-Echo hospital discharge database. Cases with primary ICD-9 code 428 were considered cases of CHF. RESULTS: Monthly CHF mortality was higher in January, declined until September and then rose steadily (p<0.05). Hospital admissions for CHF declined from May until September (moving averages analysis p<0.0001). Seasonal mortality patterns observed in Quebec were similar to those observed in France. CONCLUSION: CHF mortality in Quebec is highest during the winter and declines in the summer, similar to observations in France and Scotland. This suggests that absolute temperatures may not necessarily be that important but increased CHF mortality is observed once environmental temperatures fall below a certain "threshold" temperature. Alternatively better internal heating and warmer clothing required for survival in Quebec may ameliorate mortality patterns despite colder external environments.

Changing trends in mortality and admissions to hospital for elderly patients with congestive heart failure in Montreal.

BACKGROUND: Congestive heart failure (CHF) is a common disease requiring admission to hospital among elderly people and is associated with a high mortality rate. The objective of this study was to examine trends in CHF mortality and admissions to hospital in Montreal between 1990 and 1997 for individuals aged 65 years or more. METHODS: We obtained information about deaths from the Quebec Death Certificate Registry database and information about admissions to hospital from the Quebec Med-Echo database. Patients with a primary diagnosis that was classified as ICD-9 code 428 were considered cases of CHF. RESULTS: Although age-adjusted rates of mortality from CHF did not change significantly between 1990 and 1997, the annual rate of admission to hospital for CHF increased from 92 per 10,000 population in 1990/91 to 124 per 10,000 population in 1997/98 (p < 0.01). Deaths due to CHF, expressed as a proportion of all cardiovascular deaths, increased among women from 5.6% in 1990 to 6.2% in 1997 (p = 0.01). The rate of readmission for all causes following a first admission for CHF during that year rose over the study period from 16.6% to 22.0% within one month (p < 0.001) and from 46.7% to 49.4% within 6 months (p = 0.03). Conversely, mean annual length of stay per admission decreased from 16.4 days in 1990/91 to 12.2 days in 1997/98. INTERPRETATION: The increase in rates of admission to hospital for CHF and the stable rates of CHF mortality suggest that the management of CHF and its antecedents has improved in recent years.