Table 2.
Comparison of primary and secondary outcomes by hospital group between pre-implementation period (2014-15) and implementation period (2017-18) in hospitals assigned to prospective monitoring of outcomes using control charts with regular feedback on indicators (intervention) or to usual care (control). Values are numbers (percentages) unless stated otherwise
| Surgical outcomes | Intervention hospitals | Control hospitals | Intervention v control hospitals | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Pre-implementation | Implementation | Implementation v pre-implementation: adjusted odds ratio (95% CI) | Pre-implementation | Implementation | Implementation v pre-implementation: adjusted odds ratio (95% CI) | Adjusted ratio of odds ratios (95% CI) | P value | Intraclass correlation coefficient | |||
| All surgery (n=155 362) | |||||||||||
| Major adverse event* | 4080 (10.9) | 4163 (11.1) | 0.95 (0.90 to 1.00) | 4582 (11.0) | 4644 (12.0) | 1.07 (1.02 to 1.13) | 0.89 (0.83 to 0.96) | 0.001 | 0.033 | ||
| Death | 584 (1.6) | 528 (1.4) | 0.85 (0.75 to 0.96) | 648 (1.6) | 647 (1.7) | 1.01 (0.90 to 1.13) | 0.84 (0.71 to 0.99) | 0.04 | 0.028 | ||
| Intensive care stay | 2147 (5.7) | 2080 (5.6) | 0.89 (0.83 to 0.96) | 2319 (5.6) | 2268 (5.9) | 1.05 (0.98 to 1.13) | 0.85 (0.76 to 0.94) | 0.001 | 0.151 | ||
| Reoperation | 1584 (4.2) | 1682 (4.5) | 1.00 (0.93 to 1.07) | 1817 (4.4) | 1940 (5.0) | 1.10 (1.03 to 1.18) | 0.91 (0.82 to 1.00) | 0.06 | 0.026 | ||
| Severe complication | 1466 (3.9) | 1610 (4.3) | 1.04 (0.96 to 1.12) | 1687 (4.1) | 1812 (4.7) | 1.08 (1.01 to 1.16) | 0.96 (0.87 to 1.07) | 0.46 | 0.018 | ||
| Minor surgery† (n=103 457) | |||||||||||
| Major adverse event* | 1243 (4.8) | 1182 (4.7) | 0.91 (0.84 to 1.00) | 1321 (4.8) | 1335 (5.4) | 1.10 (1.01 to 1.20) | 0.83 (0.74 to 0.94) | 0.003 | 0.031 | ||
| Death | 157 (0.6) | 137 (0.5) | 0.85 (0.67 to 1.08) | 190 (0.7) | 186 (0.8) | 1.01 (0.82 to 1.25) | 0.85 (0.62 to 1.16) | 0.30 | 0.035 | ||
| Intensive care stay | 531 (2.0) | 474 (1.9) | 0.87 (0.76 to 1.00) | 522 (1.9) | 485 (2.0) | 1.03 (0.90 to 1.19) | 0.84 (0.69 to 1.02) | 0.08 | 0.099 | ||
| Reoperation | 575 (2.2) | 551 (2.2) | 0.91 (0.81 to 1.03) | 643 (2.3) | 679 (2.8) | 1.11 (0.99 to 1.24) | 0.82 (0.70 to 0.97) | 0.02 | 0.028 | ||
| Severe complication | 420 (1.6) | 412 (1.6) | 0.95 (0.82 to 1.09) | 472 (1.7) | 503 (2.0) | 1.13 (0.99 to 1.29) | 0.84 (0.69 to 1.02) | 0.07 | 0.027 | ||
| Major surgery‡ (n=51 905) | |||||||||||
| Major adverse event* | 2837 (24.8) | 2981 (24.4) | 0.98 (0.92 to 1.05) | 3261 (23.1) | 3309 (23.4) | 1.05 (0.99 to 1.12) | 0.93 (0.85 to 1.02) | 0.14 | 0.046 | ||
| Death | 427 (3.7) | 391 (3.2) | 0.84 (0.73 to 0.98) | 458 (3.2) | 461 (3.3) | 1.00 (0.87 to 1.15) | 0.85 (0.69 to 1.03) | 0.10 | 0.028 | ||
| Intensive care stay | 1616 (14.1) | 1606 (13.2) | 0.90 (0.83 to 0.98) | 1797 (12.7) | 1783 (12.6) | 1.06 (0.98 to 1.15) | 0.85 (0.75 to 0.95) | 0.006 | 0.180 | ||
| Reoperation | 1009 (8.8) | 1131 (9.3) | 1.05 (0.96 to 1.15) | 1174 (8.3) | 1261 (8.9) | 1.09 (1.00 to 1.19) | 0.96 (0.85 to 1.09) | 0.57 | 0.031 | ||
| Severe complication | 1046 (9.1) | 1198 (9.8) | 1.08 (0.99 to 1.18) | 1215 (8.6) | 1309 (9.3) | 1.06 (0.97 to 1.15) | 1.02 (0.90 to 1.15) | 0.77 | 0.022 | ||
Odds ratios were estimated using mixed effect logistic regression models to compare surgical outcomes between pre-implementation and implementation periods in intervention and control hospitals. Ratio of odds ratios captured the impact of the control chart by comparing the change in outcomes from the pre-implementation to implementation periods between the intervention and control hospitals based on a difference-in-differences approach. A ratio of odds ratios value less than unity indicated improvement as a result of control charts in intervention versus control hospitals. Estimates with corresponding 95% confidence interval considered clustering of patients at the hospital level. Outcomes were adjusted for a risk score that considered age, sex, presence of comorbidities, emergency admission, date and operative procedure, main diagnosis, complexity of surgical procedure, median household income for patient level covariates, and status for hospital level covariates.
Composite of surgical complications occurring at any hospital within 30 days after the surgical procedure based on Clavien-Dindo classification, including patient death, intensive care stay (at least two nights in intensive care or five nights in critical care), reoperation (open or laparoscopic digestive tract procedure), or severe complication (cardiac arrest, pulmonary embolism, sepsis, or surgical site infection).
Hernia repair, cholecystectomy, appendectomy, bariatric surgery.
Colorectal, hepatopancreatic, oesophageal and gastric surgery.