INTRODUCTION
Multiple self-reported patient-reported outcome measures (PROMs) have been developed and used to evaluate the impact of non-specific low back pain (NSLBP) on working-age adults. However, it is unclear whether they are applicable to older adults. The current systematic review aimed to summarize the measurement properties of self-reported PROMs for older adults with NSLBP.
METHODS
The current review protocol was registered in PROSPERO (#CRD42023106099). A systematic search was undertaken in eight databases. Studies in older adults with NSLBP using older people of all age ranges standard to assess one or more measurement properties of PROMs were included. The measurement properties and the methodological quality of the included articles were assessed using the 2018 version of Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) checklist and the Quality Appraisal for Clinical Measurement Research Reports Evaluation Form (QACMRR), respectively. The modified Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to rate the quality of evidence regarding the psychometric properties of the included questionnaires. Finally, the recommendations of using identified PROMs for older adults were categorized into “categories A to C”, where A is the highest recommendation.
RESULTS
Twelve included studies evaluated the measurement properties of 10 identified PROMs on older adults with NSLBP. The risk of bias for the measurement properties ranged from “inadequate” to “very good”, while the methodological quality of these studies ranged from “good” to “excellent” based on the QACMRR. None of the included studies directly evaluated the content validity and cross-cultural validity of the identified PROMs, 4 studies investigated criterion validity or structural validity, 4 studies reported construct validity, 8 studies reported internal consistency, 9 studies reported test-retest or intra-rater reliability, 3 studies reported measurement error and 3 studies reported responsiveness. The evidence of measurement properties ranged from “very low” to “high” using the modified GRADE approach. Among them, the Functional Rating Index, Oswestry Disability Index, Roland Morris Disability Questionnaire, and Quebec Back Pain Disability Scale demonstrated the highest rating (category A) by the COSMIN guideline, indicating their suitability for evaluating pain-related functional limitation or pain intensity in older adults with acute, subacute, or chronic NSLBP. The Pain Response to Activity and Positioning questionnaire was rated as category A for the differential diagnosis of chronic NSLBP in older adults. The remaining five PROMs were considered promising (category B), although further validation of these PROMs in older adults with NSLBP is warranted. Future research may develop comprehensive multi-domain questionnaires to evaluate NSLBP impacts in older adults.
DISCUSSION
This is the “first” systematic review to summarize the evidence regarding the measurement properties of various self-reported PROMs adopted for older adults with NSLBP. Although some identified PROMs may have the potential to be used in older adults, future studies on the content validity of these PROMs in older adults with NSLBP should be conducted according to the COSMIN guidelines.