The observed effect of adverse drug reactions on the length of hospital stay among medical inpatients in a Nigerian University Teaching Hospital

Background: The potential impact of an adverse drug reaction (ADR) is multidimensional, and includes prolonged length of hospitalization which significantly increased morbidity, mortality, and economic burden with additional intense medical care. Aim: This study was designed to characterize and evaluate the potential effect of ADRs on the length of hospital stay among adult medical inpatients in an academic teaching hospital in a large West African nation. The overarching goal of the study is to highlight approaches toward mitigating the sequelae of ADRs in this setting, and improving their recognition and timely optimal management. Methods: The patients admitted into the adult medical wards of a Nigerian University Teaching Hospital over a 9-month period from December 2013 to August 2014 were prospectively recruited for the study and followed up till discharge. Results: A total of 507 patients were evaluated during the study, out of which 269 (53.1%) of them were males and 238 (46.9%) were females. The mean age of the study population was 48.9 ± 17.8 years (median of 46 years). In this study, the mean duration of hospital stay for all patients was 11.9 ± 11.3 days (median of 9 days). Females had a mean duration stay of 12.9 ± 12.3 days (median of 10 days) and stayed significantly longer than males who stayed a mean duration of 10.9 ± 10.2 days with a median of 7 days (t = −1.985, df = 505, p = 0.048). Furthermore, patients admitted solely because of ADRs (ADR-out) had a significantly shorter duration of stay with a mean duration stay of 6.1 ± 3.7 days (median duration stay of 7 days) when compared to those without ADRs whose mean duration of stay was 11.6 ± 11.0 days (median duration stay of 8 days), and this was found to be statistically significant (t = 2.110, df = 472, p = 0.035). Those patients who developed ADRs during admission (ADR-in) had a mean duration of stay of 18.3 ± 14.8 (median of 15 days). This was significantly longer than the duration of stay for patients without ADRs (t = −3.398, df = 487, p = 0.001) and also significantly longer than the duration for those who were admitted solely because of ADRs (t =3.432, df = 49, p = 0.001). Conclusion: In this study, ADRs were associated with a significantly prolonged length of hospital stay for adult medical inpatients in this Nigerian University Teaching Hospital.