How physicians allocate causation: a scenario study with factorial design.
BACKGROUND
Causation is a complex concept but important in suspected work-related disease. Physicians routinely make initial assessments of causation as part of their work, but the factors contributing to these assessments are not well understood.


OBJECTIVE
To determine which factors influence a family physician's assessment of causation when seeing patients with suspected work-related injury or illness.


METHODS
Four groups of family physicians with differing levels of prior reporting (zero, low, medium, high) to the Workers Compensation Board received a questionnaire including four randomly allocated case scenarios. For each scenario there were four versions with either strong or weak causal features suggesting work or non-work factors were important causes or contributors. Responses to questions were made on a series of visual analogue scales.


RESULTS
The nature of the condition and scenario type (i.e. strength of the causal information about workplace and non-workplace factors) were associated with the physicians' opinion on work-relatedness. Understanding the nature of the patient's work, the timing of symptoms and the patients' opinion about work-relatedness were viewed by the physicians as important. A decision that a condition was not work related was influenced primarily by the strength of potential causes outside work. Prior reporting history of the physician was not associated with opinions on work-relatedness, nor the factors considered in reaching this decision.


CONCLUSIONS
The characteristics of the case scenario were more important in determining a physician's opinion about work-relatedness than the characteristics of the physician.
Division of Preventive Medicine, University of Alberta, Edmonton, T6G 2T4, Canada. jeremy.beach@ualberta.ca
J
J
Beach
Y
Y
Chen
N
N
Cherry
D000416:Alberta / Q000453:epidemiology; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology; D001291:Attitude of Health Personnel; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis / Q000453:epidemiology; D015984:Causality; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis / Q000453:epidemiology; D009784:Occupational Diseases / Q000175:diagnosis / Q000453:epidemiology; D010821:Physicians, Family; D020069:Shoulder Pain / Q000175:diagnosis / Q000453:epidemiology; D011795:Surveys and Questionnaires