Patricia W. Spitz

Abstract A structure for representation of patient outcome is presented, together with a method for outcome measurement and validation of the technique in rheumatoid arthritis. The paradigm represents outcome by five separate dimensions: death, discomfort, disability, drug (therapeutic) toxicity, and dollar cost. Each dimension represents an outcome directly related to patient welfare. Quantitation of these outcome dimensions may be performed at interview or by patient questionnaire. With standardized, validated questions, similar scores are acheived by both methods. The questionnaire technique is preferred since it is inexpensive and does not require interobserver validation. These techniques appear extremely useful for evaluation of long term outcome of patients with rheumatic diseases.

OBJECTIVE: To determine the risk and causes of death and to quantify mortality predictors in patients with rheumatoid arthritis (RA). METHODS: RA patients (n = 3,501) from 4 centers (Saskatoon n = 905, Wichita n = 1,405, Stanford n = 886, and Santa Clara n = 305) were followed for up to 35 years; 922 patients died. RESULTS: The overall standardized mortality ratio (SMR) was 2.26 (Saskatoon 2.24, Wichita 1.98, Stanford 3.08, Santa Clara 2.18) and increased with time. Mortality was strikingly increased for specific causes: infection, lymphoproliferative malignancy, gastroenterologic, and RA. In addition, as an effect of the SMR of 2.26, the expected number of deaths was increased nonspecifically across all causes (except cancer), with a large excess of deaths attributable to cardiovascular and cerebrovascular diseases. Independent predictors of mortality included age, education, male sex, function, rheumatoid factor, nodules, erythrocyte sedimentation rate, joint count, and prednisone use. CONCLUSION: Mortality rates are increased at least 2-fold in RA, and are linked to clinical severity.

The factors associated with mortality were examined in a prospective longitudinal study, over an average of 12 years, with 94% followup of patients diagnosed as having rheumatoid arthritis. Of 805 patients, 233 died during the period of the study. Survivorship of rheumatoid arthritis patients was approximately 50% less than that of population controls. Survivorship was decreased by the traditional demographic variables of greater age and male sex; however, a significant independent effect of variables reflecting disease severity (American Rheumatism Association functional class, rheumatoid factor titer, number of involved joints) was identified by multivariate analysis. Seventy-nine excess deaths (i.e., those that would not have been expected in a control population) were due in part to disease-related causes, to infections, and to gastrointestinal complications of therapy. Treatment with gold or prednisone did not seem to affect survivorship or cause of death, except for the clustering of deaths of patients with vasculitis within the prednisone group. Our findings indicate that rheumatoid arthritis, a chronic disabling disease, is also associated with a major decrease in survivorship.