Results
We identified 31,570 eligible patients during the study period. Of these, 28,145 (89.2%) were treated with glucocorticoids on the day of admission (Fig. 1).
Table 1 shows the patients’ baseline characteristics before and after propensity score matching. Before propensity score matching, significantly higher proportions of patients were using histamine-1 receptor blockers, histamine-2 receptor blockers, and beta 2-adrenergic receptor stimulants in the glucocorticoids group than in the control group.
The overall percentage of biphasic reactions within 7 days of admission was 11.2% and 7-day all-cause mortality was 0.4% (Table 2). The percentages of biphasic reactions that occurred on days 1, 2, and 3–7 of the initial reaction were 88.8%, 9.1%, and 2.1%, respectively.
One-to-four propensity-score matching created matched cohorts of 3,425 patients in the control group and 13,700 patients in the glucocorticoid group. After propensity score matching, the distribution of patient characteristics was well-balanced between the matched groups and there were no statistically significant differences in rates of biphasic reactions (odds ratio 1.03; 95% CI 0.86–1.24; p=0.14) or 7-day all-cause mortality (odds ratio 0.68; 95% CI 0.40–1.17; p=0.16) between the two groups (Table 2).
The results of three sensitivity analyses of traditional multivariable regression analyses, propensity score adjustment, and inverse probability of treatment weighting were similar to those using propensity score matching for biphasic reactions (Table 3).