Early rehospitalizations of frail elderly patients - the role of medications: a clinical, prospective, observational trial

Background and objective: Early readmissions of frail elderly patients after an episode of hospital care are common and constitute a crucial patient safety outcome. Our purpose was to study the impact of medications on such early rehospitalizations.

Patients and methods: This is a clinical, prospective, observational study on rehospitalizations within 30 days after an acute hospital episode for frail patients over the age of 75 years. To identify adverse drug reactions (ADRs), underuse of evidence-based treatment and avoidability of rehospitalizations, the Naranjo score, the Hallas criteria and clinical judgment were used.

Results: Of 390 evaluable patients, 96 (24.6%) were rehospitalized. The most frequent symptoms and conditions were dyspnea (n = 25) and worsened general condition (n = 18). The most frequent diagnoses were heart failure (n = 17) and pneumonia/acute bronchitis (n = 13). By logistic regression analysis, independent risk predictors for rehospitalization were heart failure (odds ratio [OR] = 1.8; 95% CI = 1.1-3.1) and anemia (OR = 2.3; 95% CI = 1.3-4.0). The number of rehospitalizations due to probable ADRs was 13, of which two were assessed as avoidable. The number of rehospitalizations probably due to underuse of evidence-based drug treatment was 19, all of which were assessed as avoidable. The number of rehospitalizations not due to ADRs or underuse of evidence-based drug treatment was 64, of which none was assessed as avoidable.

Conclusion: One out of four frail elderly patients discharged from hospital was rehospitalized within 1 month. Although ADRs constituted an important cause of rehospitalization, underuse of evidence-based drug treatment might be an even more frequent cause. Potentially avoidable rehospitalizations were more frequently associated with underuse of evidence-based drug treatment than with ADRs. Efforts to avoid ADRs in frail elderly patients must be balanced and combined with evidence-based drug therapy, which can benefit these patients.