The patient enablement instrument for back pain: reliability, content validity, construct validity and responsiveness.

BACKGROUND: Currently, there are no outcome measures assessing the ability of people with non-specific low back pain to self-manage their illness. Inspired by the 'Patient Enablement Instrument', we developed the Patient Enablement Instrument for Back Pain (PEI-BP). The aim of this study was to describe the development of the Patient Enablement Instrument for Back Pain (PEI-BP) and investigate content validity, construct validity, internal consistency, test-retest reliability, measurement error, responsiveness and floor and ceiling effects. METHODS: The PEI-BP consists of 6 items that are rated on a 0-10 Numeric Rating Scale. Measurement properties were evaluated using the COSMIN taxonomy and were based on three cohorts from primary care with low back pain: The content validity cohort (N = 14) which participated in semi-structured interviews, the GLA:D® Back cohort (N = 272) and the test-retest cohort (N = 37) which both completed self-reported questionnaires. For construct validity and responsiveness, enablement was compared to disability (Oswestry Disability Index), back pain beliefs (Brief Illness Perception Questionnaire), fear avoidance (Fear-Avoidance Beliefs Questionnaire-physical activity), mental health (SF-36), educational level and number of previous episodes of low back pain. RESULTS: The PEI-BP was found to have acceptable content validity, construct validity, reliability (internal consistency, test-retest reliability and measurement error) and responsiveness. The Smallest Detectable Change was 10.1 points illustrating that a patient would have to change more than 1/6 of the scale range for it to be a true change. A skewed distribution towards the high scores were found at baseline indicating a potentially problematic ceiling effect in the current population. CONCLUSIONS: The PEI-BP can be considered a valid and reliable tool to measure enablement on people seeking care for non-specific LBP. Further testing of the PEI-BP in populations with more severe LBP is recommended. TRIAL REGISTRATION: Not applicable.

Validity and reliability of State-Trait Anxiety Inventory in Danish women aged 45 years and older with abnormal cervical screening results.

BACKGROUND: State Trait Anxiety Inventory (STAI) scale was developed in the 1980's and has been widely used both in clinical settings and in research. However the Danish version of STAI has not been validated. The aim of this study was to assess the validity and reliability of STAI - state anxiety scale in Danish women aged 45 years and older with abnormal cervical cancer screening results. METHODS: Women ≥45 years referred with an abnormal cervical cytology and healthy volunteers (n = 12) underwent cognitive interview after completing STAI. Further, STAI was sent out in an electronic questionnaire to women (n = 109) seen at the gynecological department with abnormal cervical cancer screening test during 2018. Validity and reliability of STAI was evaluated according to the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist by examining internal consistency, test-retest reliability, measurement error, floor and ceiling, construct validity and content validity. RESULTS: In the cognitive interviews the content validity was evaluated to be very good. The internal consistency of the scale was excellent with Cronbach's α = 0.93. Test-retest reliability was good with an intra-class correlation coefficient of 0.80 and the systematic difference between test-retest results was negligible. The construct validity was good. CONCLUSION: To our best knowledge, this is the first validation study of the Danish translation of STAI-state anxiety scale. This version of STAI demonstrates an acceptable reliability and validity when used in a gynecological setting.