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Canadian Journal of Anaesthesia

, Volume 39, Issue 5, pp 430–439 | Cite as

The Canadian four-centre study of anaesthetic outcomes: II. Can outcomes be used to assess the quality of anaesthesia care?

  • Marsha M. Cohen
  • Peter G. Duncan
  • William D. B. Pope
  • Diane Biehl
  • W. Arnold Tweed
  • Leonard MacWilliam
  • Richard N. Merchant
Reports of Investigation
Accepted:

Abstract

Since anaesthesia, unlike medical or surgical specialties, does not constitute treatment, this study sought to determine if methods used to assess medical or surgical outcomes (that is the determination of adverse outcome) are applicable to anaesthesia. Anaesthetists collected information on patient, surgical and anaesthetic factors while data on recovery room and postoperative events were evaluated by research nurses. Data on 27,184 inpatients were collected and the analysis of outcomes determined for the intraoperative, post-anaesthetic care unit and postoperative time periods. Logistic regression was used to control for differences in patient populations across the four hospitals. In addition, a random selection of 115 major events was classified by a panel of anaesthetists into anaesthesia, surgical and patient-disease contributions. Across the three time periods, large variations in minor outcomes were found across the four hospitals; these variations ranged from two-to five-fold after case-mix adjustment (age, physical status, sex, emergency versus elective and length of anaesthesia). The rates of major events and deaths were similar across three hospitals; one hospital had a lower mortality rate (P < 0.001) but had a higher rate of all major events (P < 0.0001). Of major events assessed by physician panels, 18.3% had some anaesthetic involvement and no deaths were attributable partially or wholly to anaesthesia. Possible reasons to account for these variations in outcome include compliance in recording events, inadequate case-mix adjustment, differences in interpretation of the variables (despite guidelines) and institutional differences in monitoring, charting and observation protocols. The authors conclude that measuring quality of care in anaesthesia by comparing major outcomes is unsatisfactory since the contribution of anaesthesia to perioperative outcomes is uncertain and that variations may be explained by institutional differences which are beyond the control of the anaesthetist. It is suggested that minor adverse events, particularly those of concern to the patient, should be the next focus for quality improvement in anaesthesia.

Key words

aesthesia: epidemiology, morbidity complications: morbidity epidemiology: anaesthesia 

Résumé

Puisque l’anesthésie, contrairement aux spécialités médicales ou chirurgicales, ne constitue pas un traitement, cette étude a cherché à déterminer si les méthodes utilisées pour évaluer les issues des actes médicaux ou chirurgicaux (soit la détermination d’une issue défavorable) sont applicables en anesthésie. Les anesthésistes ont colligés l’information concernant les facteurs reliés aux patients, à la chirurgie et à l’anesthésie, alors que les données concernant la salle de réveil et les événements post-opératoires étaient évaluées par des infirmières de recherche. Des données concernant 27,184 patients hospitalisés ont été colligées et l’analyse des issues déterminée pour les périodes intra-opératoire, de salle de réveil et postopératoire. Une régression logistique a été utilisée pour contrôler les différences entre les populations de patients des quatre hôpitaux. De plus, une sélection au hasard de 115 événements majeurs a été classifiée par un groupe d’anesthésistes selon la contribution de l’anesthésie, de la chirurgie et de la maladie du patient. Pour les trois périodes considérées, de grandes variations dans les issues défavorables d’importance mineure ont été trouvées entre les quatre hôpitaux; ces variations s’étendaient de deux à cinq fois après ajustement pour la variété des cas (âge, condition physique, sexe, cas d’urgence versus cas électif, et durée de l’anesthésie). Les taux d’événements défavorables majeurs et de mortalité étaient similaires pour trois hôpitaux; un hôpital avait un taux de mortalité plus faible (P = 0,0004) mais avait un taux plus élevé pour tous les événements majeurs (P < 0,0001). Parmi les événements majeurs évalués par les groupes de médecins, 18,3% avaient un certain lien avec l’anesthésie et aucune mortalité n’était attribuable en partie ou en totalité à l’anesthésie. Les raisons pouvant expliquer ces variations dans l’issue des soins anesthésiques incluent la compliance à enregistrer les événements, un ajustement inadéquat pour la variété des cas, des différences dans l’inteprétation des variables (malgré les directives) et des différences institutionnelles dans les techniques de surveillance et les protocoles d’observation et d’inscription au dossier. Les auteurs concluent que mesurer la qualité des soins en anesthésie en comparant les issues défavorables majeures est non satisfaisant puisque la contribution de l’anesthésie à ces issues péri-opératoires est incertaine et que les variations peuvent etre expliquées par des différences institutionnelles sur lesquelles l’anesthésiste n ’a pas de contrôle. Il est suggéré que les événements difavorables mineurs, particulierement ceux qui intéressent le patient, devraient être le prochain point d’intérêt pour améliorer la qualité en anesthésie.

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Copyright information

© Canadian Anesthesiologists 1992

Authors and Affiliations

  • Marsha M. Cohen
    • 1
    • 2
    • 3
    • 4
  • Peter G. Duncan
    • 1
    • 2
    • 3
    • 4
  • William D. B. Pope
    • 1
    • 2
    • 3
    • 4
  • Diane Biehl
    • 1
    • 2
    • 3
    • 4
  • W. Arnold Tweed
    • 1
    • 2
    • 3
    • 4
  • Leonard MacWilliam
    • 1
    • 2
    • 3
    • 4
  • Richard N. Merchant
    • 1
    • 2
    • 3
    • 4
  1. 1.Department of AnesthesiaUniversity of ManitobaWinnipegCanada
  2. 2.Department of AnesthesiaUniversity of Western OntarioLondonCanada
  3. 3.Department of AnesthesiaUniversity of SaskatchewanSaskatoonCanada
  4. 4.Department of Community Health SciencesUniversity of ManitobaWinnipegCanada

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