Health-related quality of life of patients with psoriatic arthritis: a comparison with patients with rheumatoid arthritis

OBJECTIVE

To compare health-related quality of life (QOL) between patients with psoriatic arthritis (PsA) and patients with rheumatoid arthritis (RA), using the Medical Outcomes Study Short Form health survey (SF-36) and the Health Assessment Questionnaire (HAQ).

METHODS

Both the SF-36 and the HAQ were administered to 107 PsA patients attending the University of Toronto Psoriatic Arthritis Clinic between January 1 and December 31, 1994, and to 43 RA patients attending a University of Toronto-affiliated RA clinic during the same period. Standardized assessments of disease activity and severity were also performed at each clinic visit. Logistic regression analysis was used to compare health-related QOL between PsA and RA.

RESULTS

Both patient populations experienced lower physical health compared with that of a general population sample. The RA patients demonstrated more active inflammatory disease at the time of assessment than the PsA patients. The PsA patients were younger, and more were men. Logistic regression analyses showed that patients with PsA reported higher levels of vitality than patients with RA, even after adjusting for the observed differences in clinical and demographic characteristics. PsA patients, however, reported more role limitations due to emotional problems and more bodily pain after adjusting for the difference in vitality and other covariates.

CONCLUSIONS

Although both patient populations experienced reduced QOL, there were some meaningful differences in how the 2 conditions affect health-related QOL. Further, it appeared that there may be unique disabilities associated with the psoriasis dimension of PsA.

Health-related quality of life of patients with psoriatic arthritis: a comparison with patients with rheumatoid arthritis

OBJECTIVE

To compare health-related quality of life (QOL) between patients with psoriatic arthritis (PsA) and patients with rheumatoid arthritis (RA), using the Medical Outcomes Study Short Form health survey (SF-36) and the Health Assessment Questionnaire (HAQ).

METHODS

Both the SF-36 and the HAQ were administered to 107 PsA patients attending the University of Toronto Psoriatic Arthritis Clinic between January 1 and December 31, 1994, and to 43 RA patients attending a University of Toronto-affiliated RA clinic during the same period. Standardized assessments of disease activity and severity were also performed at each clinic visit. Logistic regression analysis was used to compare health-related QOL between PsA and RA.

RESULTS

Both patient populations experienced lower physical health compared with that of a general population sample. The RA patients demonstrated more active inflammatory disease at the time of assessment than the PsA patients. The PsA patients were younger, and more were men. Logistic regression analyses showed that patients with PsA reported higher levels of vitality than patients with RA, even after adjusting for the observed differences in clinical and demographic characteristics. PsA patients, however, reported more role limitations due to emotional problems and more bodily pain after adjusting for the difference in vitality and other covariates.

CONCLUSIONS

Although both patient populations experienced reduced QOL, there were some meaningful differences in how the 2 conditions affect health-related QOL. Further, it appeared that there may be unique disabilities associated with the psoriasis dimension of PsA.

Methods for assessing responsiveness: a critical review and recommendations

A review of the literature suggests there are two major aspects of responsiveness. We define the first as "internal responsiveness," which characterizes the ability of a measure to change over a prespecified time frame, and the second as "external responsiveness, " which reflects the extent to which change in a measure relates to corresponding change in a reference measure of clinical or health status. The properties and interpretation of commonly used internal and external responsiveness statistics are examined. It is from the interpretation point of view that external responsiveness statistics are considered particularly attractive. The usefulness of regression models for assessing external responsiveness is also highlighted.

The relationship between patient satisfaction with health and clinical measures of function and disease status in patients with psoriatic arthritis

OBJECTIVE

To investigate whether patient satisfaction with health is a distinct aspect of clinical or health status in a sample of patients with psoriatic arthritis (PsA).

METHODS

One hundred sixty-nine consecutive outpatients attending the University of Toronto PsA Clinic completed the Arthritis Impact Measurement Scales II (AIMS2), which includes both a global rating of patient satisfaction with health and a scale that assesses satisfaction with functioning in 12 health domains. Clinical, laboratory, and radiological assessments of function, pain, inflammation, and damage were also performed according to a standard protocol.

RESULTS

Logistic regression analysis indicated that the AIMS2 global ratings of patient satisfaction with health were not associated with traditional clinical measures of inflammation and damage, but were associated with American College of Rheumatology (ACR) functional class and number of fibromyalgia tender points. Patient satisfaction was also related to annual family income and use of retinoids or corticosteroids. Similarly, linear regression analysis showed that scores on the AIMS2 satisfaction scale were unrelated to traditional clinical measures of inflammation and damage, with the exception of total number of actively inflamed joints. ACR functional class, annual family income, and comorbidity were also related to scores on the satisfaction scale.

CONCLUSION

Patient satisfaction with health appears to be relatively independent of traditional clinical measures of physical functioning, pain, and disease status.

Validity assessment of the disabilities of arm, shoulder, and hand questionnaire (DASH) for patients with psoriatic arthritis

OBJECTIVE

To determine whether patients' perception of their functional ability, as measured by the disabilities of arm, shoulder. and hand (DASH) questionnaire, correlates with clinical measures of articular status in patients with psoriatic arthritis (PsA).

METHODS

Patients attending the University of Toronto Psoriatic Arthritis Clinic between June and August 1997 were asked to complete a DASH questionnaire during their visits. Clinical assessments were performed according to a standard protocol including number of actively inflamed joints, total number of damaged joints, and grip strength. Spearman rank correlations were used to examine the relationship between clinical measures and the DASH questionnaire.

RESULTS

Fifty consecutive patients, 28 men and 22 women, (mean age 49.2 yrs, mean disease duration 13 yrs) were included. DASH scores correlated with clinical measures of upper extremity function including right grip strength (r = -0.47, CI -0.67, -0.21) and number of active joints in the upper limbs (r = 0.65, CI 0.46, 0.79). As expected, the correlation between DASH scores and total number of active joints (r = 0.40, CI 0.14, 0.61) was lower than that between DASH scores and number of active joints in the upper limbs. The DASH was unrelated to clinical damage.

CONCLUSION

DASH is a valid instrument for assessing upper extremity function and inflammatory disease activity in patients with PsA.

Responsiveness of health status instruments to changes in articular status and perceived health in patients with psoriatic arthritis

OBJECTIVE

To compare the responsiveness of the Health Assessment Questionnaire (HAQ), Arthritis Impact Measurement Scale 2 (AIMS2), and Medical Outcome Study Short Form Health Survey (SF-36) to changes in articular status and perceived health in outpatients with psoriatic arthritis (PsA).

METHODS

The 3 health status instruments were administered in random order on 2 occasions, about 12-18 months apart, to 70 patients attending the University of Toronto psoriatic arthritis clinic. Standardized assessments of disease activity, disease severity, and general health perceptions were also performed at each clinic visit. To assess responsiveness we used: (1) linear regression analyses to relate change scores for perceived health, the number of actively inflamed, and damaged joints to change scores for selected dimensions of the HAQ, AIMS2, and SF-36; (2) logistic regression analyses to relate both improvement in disease activity and disease progression to health status change scores; and (3) standardized response means (SRM).

RESULTS

There were 43 men and 27 women with a mean age of 46 years and arthritis duration of 13 years. Univariate regression analyses showed that the individual instruments were responsive to perceived changes in health, but relatively insensitive to detect changes in articular status. Multivariate regression analyses, in which the common dimensions of the instruments were jointly entered, indicated the SF-36 was equally or more responsive to changes in number of actively inflamed joints, clinical improvement in disease activity, and perceived health than the HAQ and AIMS2. The SRM analysis also suggested that the SF-36 was the most responsive.

CONCLUSION

The SF-36 proved equally or more responsive to short term changes in perceived health and inflammatory disease activity; however, none of the instruments showed responsiveness to disease progression.

Validating the SF-36 health survey questionnaire in patients with psoriatic arthritis

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.

A modified version of the Health Assessment Questionnaire (HAQ) for psoriatic arthritis

OBJECTIVE

The purpose of the present investigation was to explore a modification of the Health Assessment Questionnaire (HAQ) to capture the functional problems associated with psoriasis as well as inflammatory arthritis in patients with psoriatic arthritis (PsA).

METHODS

During a visit to the Psoriatic Arthritis Clinic, 118 patients with PsA were asked to complete the modified version of the HAQ. The original HAQ and expanded HAQ (HAQ-SK) scores were calculated. Correlation and regression analyses were used to examine the relationship between the severity of psoriasis and the functional status as measured by the various HAQ measures.

RESULTS

The mean global HAQ score was 0.55 on a scale ranging from 0 to 3, while the mean global HAQ-SK score was 0.56, suggesting that the modification, which involved adding items to reflect those aspects of physical functioning most affected by psoriasis, did not materially change the global HAQ score. There were no significant associations between the global HAQ-SK disability score or the added psoriasis items and the severity and activity of psoriasis, as measured by the Psoriasis Area and Severity Index (PASI) (all correlations < 0.20). The only significant association was found between the patient and the clinician ratings of psoriasis severity (r = 0.49). Open-ended questions suggest that psychosocial functioning is another dimension of health status which is of concern to PsA patients.

CONCLUSION

The findings suggest that physical disabilities associated with the severity and activity of psoriasis are not captured by the HAQ or the HAQ-SK. Psychosocial functioning, an additional area of concern to PsA patients, is also not directly linked to physical functioning or to the severity of psoriasis.

Negative symptoms in the course of first-episode affective psychosis

To determine whether the prognostic implications of negative symptoms apply to functional psychotic disorders other than schizophrenia, we investigated the significance of negative symptoms in the 18-month course of individuals experiencing a first episode of affective psychosis. Although negative symptoms were found to occur during the acute phase of a major depression or a bipolar disorder with psychotic features, they did not endure and had limited prognostic value. Further, the findings suggest that enduring negative symptoms may be specific to schizophrenia.

Negative symptoms and the early course of schizophrenia

To determine the usefulness of including a duration criterion in the definition of "negative" symptoms, the prognostic significance of a longitudinally obtained measure of negative symptoms was compared with a cross-sectionally obtained measure. As predicted, the presence of negative symptoms based on longitudinal observation was associated with most aspects of 18-month course in a group of "first-episode" schizophrenic individuals, whereas cross-sectional levels of negative symptoms were not. The findings suggest that negative symptoms, when operationalized as a trait-like phenomenon, help to portend a poor course of illness.

Accuracy of registration of invasive cervical cancer

The quality of the data recorded by the British Columbia Cancer Registry for 521 new cases of invasive cervical cancer was evaluated. The registry's pathological diagnosis in all new registrations of invasive cervical cancer diagnosed in British Columbia between 1977 and 1979 was compared with a best estimate of the true diagnosis, which was determined from the results of the provincial cervical cytology screening program and the clinical charts at the Cancer Control Agency of British Columbia. The registry's data overestimated the true incidence of invasive cervical cancer by approximately 55%, since 184 (35%) of the cases were incorrectly registered. Of the 184, 141 (77%) were cases of preinvasive cervical cancer, 26 (14%) did not meet the criteria for a true case (i.e., they were not newly diagnosed in British Columbia between 1977 and 1979) and 17 (9%) were cases of invasive cancer of another primary site. In addition, 28 cases of invasive cervical cancer diagnosed in the province during the study period had not been reported to the registry. Thus, both over-reporting and under-reporting occurred. There is a need for constant evaluation of registry data if cancer registries are to fulfil their potential contribution to cancer control programs and research.