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Objective: To determine whether there has been a change in mortality rates over the last 3 decades in patients with psoriatic arthritis (PsA) whose cases were followed prospectively., Methods: Patients receiving followup care according to a standard protocol at the University of Toronto PsA Clinic between 1978 and 2004 were included. Information on patient deaths was collected prospectively. Mortality data for the general population of Ontario, Canada, stratified by 5-year age bands, sex, and calendar year from 1978 to 2004, were used to calculate the reference rates. Standardized mortality ratios (SMRs) were calculated through use of Poisson regression models for the number of observed deaths. Time trend analyses were performed through the use of 10-year "rolling-average" SMRs and followup period-specific SMRs stratified by the period of entry into clinic., Results: Of 680 patients with PsA, 106 (15.6%) (55 women and 51 men) have died. Major causes of death were disease of the circulatory system, neoplasms, diseases of the respiratory system, diseases of the gastrointestinal system, injuries/poisoning, and unknown. The overall SMR for the period 1978-2004 was 1.36 (95% confidence interval 1.12, 1.64). The estimated number of life-years lost by the PsA patient cohort overall was 2.99 years (95% confidence interval 1.14, 4.77). For patients who entered the cohort during the years 1978-1986, the SMRs were 1.89, 1.83, and 1.21 for followup periods 1978-1986, 1987-1995, and 1996-2004, respectively. For patients who entered the cohort during the years 1987-1995, the SMRs were 0.55 and 0.82, while the SMR for those who entered during 1996-2004 was 0.56., Conclusion: The drop in SMRs in this PsA clinic population suggests that the mortality risk has improved over time. This improved survival may reflect disease severity at presentation in the earlier cohort as well as earlier diagnosis and more aggressive treatment in the more recent followup period.

Rheumatological disorders are complex conditions characterized by a variety of clinical manifestations and courses in different patients with the same condition. The best way to understand the course and prognosis of these patients is through longitudinal observational cohort studies. Such studies have been facilitated by computer technology that allows tracking of large numbers of patients and visits and analysis of a large amount of data. There are requirements for such datasets to be informative: internal and external consistency; clearly defined methods of observation and measurement; complete followup; consideration of potential confounders. We describe the usefulness of an observational cohort analysis using the University of Toronto Psoriatic Arthritis Clinic Database as a model. Analysis issues are highlighted and proposed mechanisms offered for keeping patients involved to ensure complete followup is maintained.

Objective: To assess the reliability and validity of the SF-36 in patients with psoriatic arthritis (PsA)., Methods: The SF-36 was administered to all patients attending the University of Toronto Psoriatic Arthritis Clinic between January and December 1994. Clinical and radiological assessments were performed during the clinic visits., Results: We studied 113 patients, 43 women and 70 men, with a mean age of 50.5 years and a mean arthritis duration of 14.2 years. The reliability of the SF-36 was high, with the Cronbach alpha coefficient exceeding 0.90 for all the 8 health scales. The SF-36 was able to detect meaningful differences in health status between patients with PsA and individuals from the general population. As predicted, patients with PsA reported substantially lower scores on the physical functioning, role limitations due to physical problems, and pain scales. They also reported significantly lower scores on the role limitations due to emotional problems and general health perception scale. In general all scales were moderately to highly correlated with measures of function and pain (r = 0.33-0.67), while the physical functioning, pain, and vitality scales were also moderately correlated with disease activity (r = 0.34-0.42). With one exception the scales were unrelated to disease severity., Conclusion: The SF-36 questionnaire is reliable and valid for use in PsA, supporting its use as an adjunct outcome measure for clinical trials in PsA. Because the SF-36 can be used to compare health status across different patient populations, its application can also help to clarify the disease burden associated with PsA.