Screening an elderly population for verifiable adverse drug reactions. Methodological approach and initial data of the Berlin Aging Study (BASE).

Older adults are known to carry the largest risk for potential adverse drug reactions (ADR) due to the increased number of diseases and concurrent drug therapies. Prevalence rates of the most frequently used drugs in this population have already been evaluated, but the actual rates of specific drug-related risks (e.g., renal dysfunction) have not. Precise estimates of specific ADR risks rely on careful evaluation of the complete drug regimen for potential adverse effects, especially for elderly subjects. In addition, evaluations of manifest ADR have generally been based on reviews of individual medical records of self-reported symptoms. Systematic screening of a representative sample of elders for verifiable potential ADR has not been performed to date and is methodologically challenging. However, the present study attempts to assess both the prevalence of explicitly defined risks for known ADR and the corresponding co-occurrence of laboratory parameter alterations using a new approach. Initial findings are reported for a nearly-representative, age and sex stratified sample of 70 to 100+ year old subjects (n = 336) who participated in the Berlin Aging Study (BASE). Analyses focused on adverse drug effects on fluid and electrolyte balance and renal function. The results indicated an overall prevalence rate of 50% for selected ADR risks and a rate of 26% for the co-occurrence of corresponding laboratory alterations. By taking age into account, preliminary multivariate analyses did not support the hypothesis of increasing ADR susceptibility with advancing age.