Therapeutic failure-related hospitalisations in the frail elderly

Although therapeutic failure may be a common cause of drug-related morbidity in older adults, few studies have focused on this problem. The study objective was to determine the frequency and types of, and the factors associated with, therapeutic failure leading to hospitalisation in frail, elderly patients, using a new instrument named the Therapeutic Failure Questionnaire (TFQ).

The sample included 106 frail, hospitalised elderly patients enrolled in a 1-year-long health service intervention trial at 11 Veterans Affairs Medical Centres. The TFQ was developed by a team of clinical geriatricians and tested for reliability by two clinical pharmacists and a geriatrician on a sample of 32 patients. To establish validity, a geriatrician retrospectively reviewed the computerised medication records and clinical charts for these patients and applied the TFQ to determine probable therapeutic failures at the time of hospital admission.

Inter- and intra-rater reliability for the TFQ were very good (kappa = 0.82 for both). Overall, 11% of patients had one or more probable therapeutic failures (TFQ scores between 4 and 7) leading to hospitalisation. Cardiopulmonary disease was a common 'indicator' of therapeutic failure and was often the result of non-adherence. The only factor associated with therapeutic failure occurrence was severe chronic kidney disease (crude odds ratio 5.87; 95% CI 1.20, 28.69; p = 0.01).

The TFQ was able to identify several cases of probable therapeutic failure leading to hospitalisation in frail, elderly patients. Non-adherence to effective therapies for chronic serious cardiopulmonary disease was a common cause of therapeutic failure and represents a target for interventions to reduce hospitalisation. Further research on the occurrence, risk factors for and types of therapeutic failure is needed in a larger cohort of older non-veterans.