Rasch analysis suggests that health assessment questionnaire II is a generic measure of physical functioning for rheumatic diseases: a cross-sectional study.

BACKGROUND: Versions of the Health Assessment Questionnaire (HAQ) are commonly used to measure physical functioning across multiple rheumatic diseases but there has been no clear demonstration that any HAQ version is actually generic. This study aimed to show that the HAQ-II instrument is invariant across different rheumatic disease categories using the Rasch measurement model, which would confirm that the instrument is generic. METHODS: HAQ-II responses from 882 consecutive rheumatology clinic attendees were fitted to a Rasch model. Invariance across disease was assessed by analysis of variance of residuals implemented in RUMM2030. Rasch modeled HAQ-II scores across disease categories were compared and the mathematical relationship between raw HAQ-II scores and Rasch modeled scores was also determined. RESULTS: The HAQ-II responses fitted the Rasch model. There was no substantive evidence for lack of invariance by disease category except for a single item ("opening car doors"). Rasch modeled scores could be accurately obtained from raw scores with a cubic formula (R2 0.99). Patients with rheumatoid arthritis had more disability than patients with other kinds of inflammatory arthritis or autoimmune connective tissue disease. CONCLUSIONS: The HAQ-II can be used across different rheumatic diseases and scores can be similarly interpreted from patients with different diseases. Transforming raw scores to Rasch modeled scores enable a strictly linear, interval scale to be used. It remains to be seen how that would affect interpretation of change scores. TRIAL REGISTRATION: ANZCTR ACTRN12617001500347 . Registered 24th October 2017 (retrospectively registered).

Risk factors for general medicine readmissions and association with mortality.

AIMS: To investigate general medicine readmissions for risk factors and association with mortality. METHOD: A case control study was performed comparing the characteristics of 30-day general medicine patients readmitted between 1 January to 30 June 2012 to a general medicine service at Capital and Coast District Health Board (Wellington region, New Zealand) with an equal number of randomly selected patients not readmitted to the service during the same time period. RESULTS: 197 patients discharged from general medicine were readmitted during the 6-month study period. There were no differences in the sex, ethnicity, residential care at admission, history of dementia, length of admission or weekend discharge of readmitted patients compared to non-readmitted patients. The mean age, number of medications and comorbidities score were higher in the readmission group. Readmission (even after controlling for age, polypharmacy, and comorbidities) was a strong predictor of 1-year all-cause mortality, with an odds ratio of 2.2. Twenty-one percent of readmission patients had more than one general medicine readmission, up to 30 days between each, with even higher mortality rate compared to one readmission (49% vs. 28%). CONCLUSION: Readmission to general medicine is strongly associated with older age, polypharmacy, and multiple comorbidities. Readmission is an independent strong risk factor for 1-year mortality, with this risk increasing after multiple readmissions. Readmissions can be a marker of deteriorating patient's condition, and a discussion in relation to prognosis, ceiling of treatment, resuscitation status documentation and advance directive may be warranted.

The patient activity scale-II is a generic indicator of active disease in patients with rheumatic disorders.

OBJECTIVE: To determine whether the Patient Activity Scale-II (PAS-II) is a generic measure of disease activity by assessing whether the relationship of PAS-II with treatment decision (indicating disease activity) is invariant across disease. METHODS: The Health Assessment Questionnaire-II (HAQ-II), a 10 cm visual analog scale for "pain," and another for "patient global assessment" were recorded from 1000 consecutive patients attending rheumatology outpatient clinics. Active disease was defined as treatment intensity increased and inactive disease was defined as treatment intensity unchanged or decreased. A logistic regression analysis was conducted with active disease as the dependent variable and the predictor variables were PAS-II, diagnostic category, and the interaction between diagnostic category and PAS-II. RESULTS: PAS-II had a weak but statistically significant association with active disease that was independent of diagnosis. An increase of 1 point in PAS-II increased the odds of being in the active disease state by 1.19 (95% CI 1.10 to 1.37). The relationship between active disease state and PAS was not affected by diagnostic category. CONCLUSION: PAS-II can be used as a generic self-report indicator of active disease across different rheumatic disorders, and not just in rheumatoid arthritis. The strength of the relationship with disease activity is weak and physician-derived indicators remain very important.