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Using clinical databases to evaluate healthcare interventions

  • Sheila Harvey (a1), Kathy Rowan (a2), David Harrison (a2) and Nick Black (a1)

Abstract

Objectives: The aim of this study was to test the feasibility of conducting rigorous, nonrandomized studies (NRSs) of healthcare interventions using existing clinical databases in terms of the following: recruiting a large representative sample of hospitals, identifying eligible cases, matching cases to controls to achieve similar baseline characteristics, making meaningful comparisons of outcomes, and carrying out subgroup analyses.

Methods: Data were extracted from the Intensive Care National Audit & Research Centre's Case Mix Programme Database to investigate the impact of management with a pulmonary artery catheter (PAC) in intensive care unit (ICU) patients. Participating ICUs were invited to collect additional data for the analysis. Patients managed with a PAC were matched to control patients on their propensity score. Hospital mortality was then compared between the two groups.

Results: Of 117 eligible ICUs, 68 (58 percent) agreed to participate, of which 57 (84 percent) collected additional data. Although a slightly higher proportion of larger ICUs in university hospitals participated, the patient case-mix was similar to that in nonparticipating ICUs. Almost all patients managed with a PAC (98 percent) were successfully matched to patients managed without a PAC. The two groups were similar for baseline characteristics. However, hospital mortality was worse for PAC patients than for non-PAC patients (odds ratio, 1.28; 95 percent confidence interval, 1.06–1.55). Subgroup analysis suggested that the impact of management with a PAC was modified by severity of illness.

Conclusions: Rigorous NRSs are feasible if they are based on data from high-quality clinical databases. However, the reliability of estimated treatment effects from such studies requires further investigation.

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References

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1. Afessa, B, Spencer, S, Khan, W, et al. Association of pulmonary artery catheter use with in-hospital mortality. Crit Care Med. 2001;29:11451148.
2. Altman, DG, Schulz, KF, Moher, D, et al. The revised CONSORT statement for reporting randomized trials: Explanation and elaboration. Ann Intern Med. 2001;134:663694.
3. Barton, S. Which clinical studies provide the best evidence? The best RCT still trumps the best observational study. BMJ. 2000;321:255256.
4. Black, N. Why we need observational studies to evaluate the effectiveness of health care. BMJ. 1996;312:12151218.
5. Byar, DP. Why data bases should not replace randomized clinical trials. Biometrics. 1980;36:337342.
6. Canto, JG, Kiefe, CI, Williams, OD, Barron, HV, Rogers, WJ. Comparison of outcomes research with clinical trials using preexisting data. Am J Cardiol. 1999;84:923927, A6.
7. Chittock, DR, Dhingra, VK, Ronco, JJ, et al. Severity of illness and risk of death associated with pulmonary artery catheter use. Crit Care Med. 2004;32:911915.
8. Connors, AF Jr, Speroff, T, Dawson, NV, et al. The effectiveness of right heart catheterization in the initial care of critically ill patients. SUPPORT Investigators. JAMA. 1996;276:889897.
9. Cook, D, Heyland, D, Marshall, J. On the need for observational studies to design and interpret randomized trials in ICU patients: A case study in stress ulcer prophylaxis. Intensive Care Med. 2001;27:347354.
10. DocDat.Org. http://www.docdat.org (accessed October 4, 2007).
11. Feinstein, AR, Horwitz, RI. Problems in the “evidence” of “evidence-based medicine”. Am J Med. 1997;103:529535.
12. Guyatt, G. A randomized control trial of right-heart catheterization in critically ill patients. Ontario Intensive Care Study Group. J Intensive Care Med. 1991;6:9195.
13. Harrison, DA, Brady, AR, Rowan, K. Case mix, outcome and length of stay for admissions to adult, general critical care units in England, Wales and Northern Ireland: The Intensive Care National Audit & Research Centre Case Mix Programme Database. Crit Care. 2004;8:R99R111.
14. Harrison, DA, Parry, GJ, Carpenter, JR, Short, A, Rowan, K. A new risk prediction model for critical care: The Intensive Care National Audit & Research Centre (ICNARC) model. Crit Care Med. 2007;35:10911098.
15. Harvey, S, Harrison, DA, Singer, M, et al. for the PAC-Man study collaboration. Assessment of the clinical effectiveness of pulmonary artery catheters in management of patients in intensive care (PAC-Man): A randomised controlled trial. Lancet. 2005;366:472477.
16. Hlatky, MA, Califf, RM, Harrell, FE Jr, et al. Comparison of predictions based on observational data with the results of randomized controlled clinical trials of coronary artery bypass surgery. J Am Coll Cardiol. 1988;11:237245.
17. Horwitz, RI, Viscoli, CM, Clemens, JD, Sadock, RT. Developing improved observational methods for evaluating therapeutic effectiveness. Am J Med. 1990;89:630638.
18. Murdoch, SD, Cohen, AT, Bellamy, MC. Pulmonary artery catheterization and mortality in critically ill patients. Br J Anaesth. 2000;85:611615.
19. Padkin, A, Rowan, K, Black, N. Using high quality clinical databases to complement the results of randomised controlled trials: The case of recombinant human activated protein C. BMJ. 2001;323:923926.
20. Peters, SG, Afessa, B, Decker, PA, et al. Increased risk associated with pulmonary artery catheterization in the medical intensive care unit. J Crit Care. 2003;18:166171.
21. Pocock, SJ, Elbourne, DR. Randomized trials or observational tribulations? N Engl J Med. 2000;342:19071909.
22. Rhodes, A, Cusack, RJ, Newman, PJ, Grounds, RM, Bennett, ED. A randomised, controlled trial of the pulmonary artery catheter in critically ill patients. Intensive Care Med. 2002;28:256264.
23. Rosenbaum, PR, Rubin, DB. The central role of the propensity score in observational studies for causal effects. Bioimetrika. 1983;70:4155.
24. Sakr, Y, Vincent, JL, Reinhart, K, et al. Use of the pulmonary artery catheter is not associated with worse outcome in the ICU. Chest. 2005;128:27222731.
25. Wunsch, H, Brady, AR, Rowan, K. Impact of exclusion criteria on case mix, outcome, and length of stay for the severity of disease scoring methods in common use in critical care. J Crit Care. 2004;19:6774.

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Using clinical databases to evaluate healthcare interventions

  • Sheila Harvey (a1), Kathy Rowan (a2), David Harrison (a2) and Nick Black (a1)

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