Results
The patients that were admitted over a one-year period in all the six medical wards were followed up. A total of 1280 patients were admitted to 162-bed medical wards of the department of internal medicine and accounted for 16038 patients’ days. The median (range) length of hospital stay was 9 (1-153) days. The mean age of the patients was 49.3±18.2, and the age range was 13-100 years. The male to female ratio was 1.4:1. Eight hundred and eighty-eight patients (70.1%) had at least a secondary level of education. Patients aged 60 years and above constituted about one-third, 418(32.7%) of all the patients admitted during the study period (Table 1).
There were 69 ADRs observed among 67 (5.2%) patients of those admitted of whom 46 (3.6%) had ADRs during hospitalisation. Majority of the observed ADRs, 61 (91%) were preventable (Table 2). Gastrointestinal tract (GIT), 37% was the most affected presenting as upper gastrointestinal bleeding (Figure 1). Twelve patients (17.9%) had fatal ADRs and 7(10.4%) deaths among the patients were related to the ADRs (Figure 2).
Implicated drugs for ADRs included non-steroidal anti-inflammatory drugs (NSAIDs), 14 (20.3%) and hypoglycaemic agents, 12 (17.4%) resulting in upper gastrointestinal bleeding and hypoglycaemia respectively. Other serious ADRs reported included Steven-Johnson’s syndrome 7.5 % (5/67) and Toxic Epidermal Necrolysis 1.5% (1/67) Table 3.
The median(range) number of drugs used by the patients within a month before admission, and while on admission were 3 (0-16) and 6 (0-28) respectively. There was no statistically significant relationship between the number of drugs taken a month before admission and development of ADRs [t=0.3 (1.1, 0.8), p=0.79]. Similarly, the relationship between the number of drugs used while on admission and the development of ADRs was not statistically significant [t=0.8 (1.4, 0.6), p=0.40). However, number of drugs on discharge was significantly less in patients with ADRs.
Of the 67 patients that developed ADRs, 7 (10.4%) died, representing the overall ADRs case fatality rate of 0.47%. Majority of the patients 5/7 (71.4%) were admitted because of the ADRs, and 2 (28.6%) had background HIV infection. Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis 3 (42.9%) were the most reported ADRs, and skin was the most affected organ/system, 4 (57.1%) that resulted in deaths of the patients. Antimicrobial agents 3 (42.9%) represented the most implicated drug class. The median(range) length of hospital stay among the patients was 8 (42) days (Table 4).
Alcohol intake [ RR (95% CI) = 1.7 (1.04, 2.80] and duration of hospital stay [ RR (95% CI) = 2.0 (1.16, 3.26] were statistically significantly related to the development of ADRs (Table 5).