The ASA Physical Status Classification: Inter-observer Consistency

Abstract

The American Society of Anesthesiologists (ASA) physical status classification system has previously been shown to be inconsistently applied by anaesthetists. One hundred and sixty questionnaires were sent out to all specialist anaesthetists in Hong Kong. Ten hypothetical patients, identical to those of a similar study undertaken 20 years ago, each with different types and degrees of physical disability were described. Respondents were asked about their country of training and type of anaesthetic practice and to assign an ASA classification status for each patient. Ninety-seven questionnaires were returned (61%) after two mailings. Agreement for each patient within groups, between groups and overall comparisons were made. Percentage of agreement was between 31 to 85%. Overall correlation was only fair in all groups (Kappa indices: 0.21-0.4). We found that the current pattern of inter-observer inconsistency of classification was similar to that 20 years ago and exaggerated between locally and overseas trained specialists (P<0.05). The validity of the ASA system, its usefulness and the need for a new, more precise scoring system is discussed.

A Review of Risk Scoring Systems Utilised in Patients Undergoing Gastrointestinal Surgery

“…5 The weakness of the ASA score apart from its subjectivity, is its wide inter-observer variability. [4][5][6][7][8] As such, it is hard to use to compare units. The ASA grade has been shown to be a good predictor of post-operative mortality 9 and better in this regard than the Goldman CRIA.…”

“…[4][5][6][7][8] The ASA score has been used to categorise pre-operative risk and is a good indicator of post-operative mortality. 9 It does not, however, provide a quantitative assessment of morbidity and mortality risk and is better at risk stratification.…”

Preoperative Risk Stratification for Mortality and Major Morbidity in Major Colorectal Surgery

“…1,4,9 DISEASES OF THE COLON & RECTUM VOLUME 52: 7 (2009) Nonetheless, a limitation is that allocation of ASA status is prone to interobserver allocation variation, [27][28][29][30] and further, this means that it is potentially prone to allocation bias. Otherwise, it remains a practical and well-established classification tool.…”

Identifying and reporting risk factors for adverse events in endoscopy. Part I: cardiopulmonary events

“…However, older studies showed low consistency (Ͻ60%) in hypothetical patients, 25 and more recent ones show poor interobserver reliability ( ϭ 0.21-0.40). 26 The latter has also never been assessed for endoscopists or endoscopy staff. Differentiating the first 3 grades is especially subjective, so this variable is often dichotomized as III or above in predictor studies.…”