Table 2 Comparison of reporting rates by type of unit and location of hospital.
| Type of unit | Baseline | End | Significance of the interaction term† | Absolute difference (SEM)‡ | ||||
|---|---|---|---|---|---|---|---|---|
| Control reports | Intervention reports | Rate ratio* (95% CI) | Control reports | Intervention reports | Rate ratio* (95% CI) | |||
| Reporting rates/10 000 OBDs | ||||||||
| ICU | 22.3 (9/4043) | 89.5 (108/12 068) | 0.2 (0.1 to 0.5) | 17.0 (7/4107) | 118.2 (153/12 943) | 0.1 (0 to 0.3) | 0.094 | 34.0 (31.7) |
| Surgical | 39.7 (87/21 891) | 43.2 (47/10 880) | 0.9 (0.6 to 1.3) | 71.9 (140/19 458) | 150.8 (165/10 940) | 0.5 (0.4 to 0.6) | <0.001 | 76.3 (29.7) |
| Medical | 79.1 (146/18 446) | 96.7 (243/25 125) | 0.8 (0.7 to 1.0) | 141.0 (313/22 197) | 243.1 (612/25 178) | 0.6 (0.5 to 0.7) | <0.001 | 84.5 (30.4) |
| Total inpatient reporting | 54.5 (242/44 380) | 82.8 (398/48 073) | 0.7 (0.56 to 0.77) | 101.0 (462/45 762) | 189.6 (930/49 061) | 0.5 (0.5 to 0.6) | <0.001 | 60.3 (18.6) |
| Reporting rates/10 000 ED attendances | ||||||||
| ED | 21.5 (85/39 504) | 6.3 (24/37 781) | 3.4 (2.2 to 5.4) | 22.2 (86/38 760) | 46.5 (181/28 888) | 0.4 (0.3 to 0.5) | <0.001 | 39.5 (11.5) |
| Reporting rates/10 000 OBDs and 10 000 ED attendances (combined) | ||||||||
| Anonymous¶ | 2.1 (18/83 884) | 0.7 (6/85 854) | 5.9 (2.4 to 13.5) | 5.1 (43/84 552) | 23.9 (186/77 949) | 0.32 (0.21 to 0.53) | <0.001 | 20.2 (3.9) |
| Regional | 55.2 (112/20 283) | 73.5 (156/21 227) | 0.75 (0.6 to 1.0) | 59.7 (112/18 775) | 208.1 (471/22 628) | 0.29 (0.2 to 0.3) | <0.001 | 130.1 (26.6) |
| Major city | 33.8 (215/63 601) | 41.2 (266/64 627) | 0.82 (0.7 to 1.0) | 66.3 (436/65 747) | 97.4 (640/65 681) | 0.68 (0.6 to 0.8) | <0.001 | 23.7 (11.8) |
ED, emergency department; ICU, intensive care unit; OBD, occupied bed day.
*Comparison made using Fisher's exact test.
†Comparison between baseline and end of intervention made using negative binomial regression analysis adjusting for clustering by hospitals. To test for the significance of the intervention effect, the statistical significance of the interaction term was assessed using the interaction term and exposure of patient discharges, with the exception of ICUs, where Poisson regression analysis used robust variance.
‡Absolute difference in change in reporting rates per 10 000 OBDs (inpatient units) or 10 000 ED attendances between intervention and control units at the end of the study compared with those at baseline.
¶Anonymous reports during the baseline period and in control units refer to those reports in where the professional designation of the reporter is not given. Anonymous reports during the study period in the intervention units refer to those reports where either the location (n = 63) or the professional designation of the reporter (n = 22), or both (n = 101), were not given by the reporter.