What is the clinical evidence from this study?

Study design: Observational. Population: Elective abdominal aortic aneurysm (AAA) (n=19638). Intervention: Postoperative complications vs. No complications. Primary outcome: Death (OR 12.22, 95% CI 10.51 to 14.21, p=< 0.001).

September 9, 2014Open Access

Failure-to-rescue and interprovider comparisons after elective abdominal aortic aneurysm repair

Q: What are the key findings of this study?

Postoperative complications after elective AAA repair were associated with significantly higher mortality (OR 12.22; 95% CI 10.51-14.21), despite systematic under-reporting in administrative data.

Key Result

Postoperative complications after elective AAA repair were associated with significantly higher mortality (OR 12.22; 95% CI 10.51-14.21), despite systematic under-reporting in administrative data.

Study Design

Type

Observational (n=19,638)

Multicenter

Yes

PICO

Population

Elective abdominal aortic aneurysm (AAA) (n=19,638)

Intervention / Comparator

Postoperative complications vs No complications

Primary Outcome

Death — OR 12.22 (10.51 to 14.21), p=< 0.001

Main Result

Effect estimate: OR 12.22 (95% CI 10.51 to 14.21)

p-value: p=< 0.001

Limitations

Systematic under-reporting and miscoding of complications in administrative data compared to case-note review, requiring concurrent validation for interprovider comparisons.

Abstract

BACKGROUND: The use of postoperative complication rates to derive metrics such as failure-to-rescue (FTR) is of increasing interest in assessing the quality of care. The aim of this study was to quantify FTR rates for elective abdominal aortic aneurysm (AAA) repair in England using administrative data, and to examine its validity against case-note review. METHODS: A retrospective observational study using Hospital Episode Statistics (HES) data was combined with a multicentre audit of data quality. All elective AAA repairs done in England between 2005 and 2010 were identified. Postoperative complications were extracted, FTR rates quantified, and differences in FTR and in-hospital death rates established. A multicentre case-note review was performed to establish the accuracy of coding of complications, and the impact of inaccuracies on FTR rates derived from HES data. RESULTS: A total of 19 638 elective AAA repairs were identified from HES; the overall mortality rate was 4·6 per cent. Patients with complications (19·2 per cent) were more likely to die than those without complications (odds ratio 12·22, 95 per cent c.i. 10·51 to 14·21; P < 0·001) and had longer hospital stays (P < 0·001). FTR rates correlated strongly with death rates, whereas complication rates did not. On case-note review (661 procedures), 41·5 per cent of patients had a complication recorded in the case notes. There was evidence of systematic under-reporting of complications in HES, leading to an overall misclassification rate of 36·3 (95 per cent c.i. 33·7 to 39·2) per cent (P < 0·001), which was less pronounced for surgical complications (12·6 (11·1 to 13·9) per cent; P <0·001). Despite this, the majority of FTR rates derived from HES were not significantly different from those derived from case-note data. CONCLUSION: Postoperative complication and FTR rates after elective AAA repair can be derived from HES data. However, use of the metric for interprovider comparisons should be done cautiously, and only with concurrent case-note validation given the degree of miscoding identified.