Evidence on the measurement properties of health-related quality of life instruments is largely missing in patients with low back pain: A systematic review

Objective: To synthesize the measurement properties of six health-related quality of life instruments (Short Form 36 [SF-36], Short Form 12 [SF-12], EuroQol 5D-3L [EQ-5D-3L], EuroQol 5D-5L [EQ-5D-5L], Nottingham Health Profile (NHP), and Patient-Reported Outcome Measurement Information System Global Health [PROMIS-GH-10]) in patients with low back pain (LBP).

Study design and setting: Six electronic databases (MEDLINE, EMBASE, CINAHL, PsycINFO, SportDiscus, and Google Scholar) were searched (July 2017). Studies assessing any measurement property in nonspecific LBP patients were included. Two reviewers independently screened the articles and assessed the risk of bias (COSMIN checklist). Consensus-based criteria were used to rate measurement properties results as sufficient, insufficient, or inconsistent; a modified GRADE approach was adopted for evidence synthesis.

Results: High quality evidence was found for insufficient construct validity of SF-36 summary scores, and EQ-5D-3L utility and visual analogue scale scores. Moderate evidence was found for sufficient construct validity of SF-12 physical summary score and inconsistent responsiveness of EQ-5D-3L utility score. Very low quality evidence was found on each instrument's content validity; very low to low evidence underpinned the other assessed measurement properties. EQ-5D-5L, NHP and PROMIS Global Health-10 were not evaluated in LBP patients.

Conclusion: Documentation of the measurement properties of health-related quality of life instruments in LBP is incomplete. Future clinimetric studies should prioritize content validity.