Trends in risk factor control in Germany 1984-1998: high blood pressure and total cholesterol

Diagnosis and treatment of the two primary cardiovascular risk factors, hypertension and hypercholesterolaemia, are well established. Nevertheless, according to earlier analyses of representative health questionnaire and examination surveys in 1984, 1988 and 1991, control of risk factors in the sense of normalized values through drug therapy did not improve to any relevant degree in former West Germany. The National Health Survey of 1998 now allows the reconsideration of the hypothesis that medical treatment has been improving and lead to a reduction of risk factor values measured in the population.

Datasets of independent cross-sectional studies in 1984, 1988, 1991 and 1998 with net random sample sizes between 3,458 and 5,335 were analysed for actual (persons with elevated values and persons successfully treated) and population (persons with elevated values) prevalence, awareness of the risk factors under question, treatment coverage (risk factor aware and treated) and effectiveness (risk factor aware, treated and normalized), and the resulting parameters of controlled (successfully treated persons among actual prevalence) and uncontrolled prevalence (persons with elevated values among actual prevalence), respectively. Thresholds chosen were blood pressure values >or=160/95 mmHg for hypertension and values >or=250 mg/dl for hypercholesterolaemia. Regarding medication, the answer of 'one to two times weekly' or more was considered to indicate a relevant drug intake.

For hypertension the population prevalence (population 30-69 years old) increased significantly (P < 0.0001) from 19.6% to 24.0% between 1984 and 1998, whereas the actual prevalence rose less steeply but still significantly (P < 0.0002) from 32.5% to 34.4%. For hypercholesterolaemia the population prevalence stagnated at 37.0% (1998), whereas the actual prevalence was 47.5% in 1998 (39.1% in 1984; P < 0.0001). For hypertension treatment, coverage improved from 45.4% to 63.0%, but treatment effectiveness decreased from 51.7% to 41.3%, both trends being highly significant. For hypercholesterolaemia, awareness increased from 18.3% to 57.6%, but treatment coverage decreased from 33.5% to 15.5%, whereas treatment effectiveness improved from 23.8% to 47.7%, all trends being highly significant (P < 0.0001).

The results do not support the hypothesis that medical care for the large population at cardiovascular risk in (Western) Germany was adequate and successful in the 1980s and 1990s.