Relationship between caseload volume and outcome for systemic lupus erythematosus treatment: the experience of Taiwan

To determine if a physician's experience or hospital caseload volume is associated with in-hospital mortality of patients with systemic lupus erythematosus (SLE).

We used data from Taiwan's National Health Insurance Research Database covering 2002 to 2004. A total of 8536 hospital admissions citing a principal diagnosis of SLE were selected. Hospitals with an average of > 50, 26-50, and < 26 SLE cases per year were categorized as high, medium, and low-caseload-volume hospitals, respectively. Physician caseload volume was defined as low (< 1 SLE case per year), medium (1-3 cases per year), and high-volume (> 3 cases per year). Multivariate logistic regression analyses employing generalized estimated equations were performed to assess the independent association between physician or hospital SLE caseload volume and in-hospital mortality, after adjusting for other factors.

We found that in-hospital mortality declined with increasing physician caseload volume (3.0%, 1.0%, and 0.8% for low, medium, and high-volume physicians, respectively), with the adjusted odds of in-hospital mortality for patients treated by low-volume physicians being 2.681 (p < 0.05) times greater than for patients treated by medium-volume physicians, and 3.195 (p < 0.001) times greater than for those treated by high-volume physicians. No significant relationship was found between in-hospital mortality and hospital SLE caseload volume (p = 0.896).

We concluded that the factor of physicians' experience treating SLE is more crucial in determining in-hospital mortality than a hospital's annual SLE caseload.