2019, Vol. 1, Issue 1, Part A

To evaluate the prevalence and financial impact of medication responses resulting in or extending hospitalization. To find major adverse responses, every patient hospitalized to an internal medicine ward for more than six months was examined. At the time of the adverse drug response (ADR), or at the time of admission, the number of drug classes was tallied. Excess ADR-related hospitalization was calculated using the following methods: a) raw excess length of stay; b) adjustment for age, sex, and the number of drug classes; and c) investigator estimation of excess length of stay. A total of 329 patients were assessed: 212 male and 117 female, with a mean age of 57.2 (males: 52.2, females: 66.2 (P0.05)), ranging from 17 to 95 years.

They spent a total of 3720 days in the hospital (mean stay 11.3 days). 298 patients (mean age 55.7, taking a mean of 2.7 drug classes, staying a mean of 10.7 days in the hospital) had no ADRs; 31 patients (mean age 84, taking 6.3 drug classes, staying a mean of 15.1 days) had ADRs; and 21 patients (mean age 63.6, taking 4.2 drug classes, staying a mean of 19.2 days, P0.01 vs patients without ADRs) had ADRs. Four ADRs (or 13% of ADRs, 40%) were deadly. Raw ADR-related extra hospital stay accounted for 318 days (8.6% of all hospital days), 282 days (7.6% of all hospital days) with multivariate adjustment, and 197 days (5.3% of all hospital days) with investigator estimation. Upon admission, the point prevalence of ADRs was 3%.

There were 5.6 incidents per 1000 patient days in hospitals. ADR-related hospitalizations were about 3% of the total. Moreover, severe ADRs were present in 6.6% of hospitalized patients. ADRs accounted for between 5 and 9% of hospital expenses. ADRs were linked to the pharmacological characteristics of the medications implicated in 24 out of 31 individuals (77%), and some of them may have been preventable.