Capturing the full measure of patient outcome improvement using a self-assessed health adjustment.

Rationale: Self-assessed health (SAH) status is a very simple four-, or five-category self-reported measure of health status that has been shown to be a powerful predictor of mortality, service use and total cost of medical care treatment. It is therefore reasonable to suggest that pre-intervention SAH may influence the extent to which patient outcomes improve following surgery.

Methods: Using the four-category measure of SAH of Excellent; Good; Fair; Poor, we developed an adjustment factor based on the mean improvement of the SAH category relative to the mean improvement of the overall sample.

Results: The results clearly indicate that the higher patients rated their pre-operative health, the greater their pre-post-operative improvement. Adjusting the outcome improvement by this SAH factor provides for the adjustment of the overall sample results by extent to which each category of SAH contributes to the overall mean.

Conclusion: The results indicate that by adjusting patient outcome improvement measures by a factor based on pre-intervention SAH, overall sample patient outcome improvement increased 5.8%. The results also indicate that failure to adjust for pre-intervention SAH will result in an understatement of patient outcome improvement following surgery.