Hip osteoarthritis and occupational mechanical exposures: a systematic review and meta-analysis

Abstract

Objectives: The aim was to conduct a systematic review and meta-analysis investigating the association between occupational mechanical exposures and hip osteoarthritis.

Methods: The study was registered in PROSPERO. A systematic literature search was conducted in six databases to identify relevant articles. Two authors independently excluded articles, extracted data, assessed the risk of bias of each included article, and graded the level of evidence. We conducted a meta-analysis using random-effects model and performed a sensitivity analysis stratifying articles based on the risk of bias assessment, study design, and the outcome measurement.

Results: Twenty-four articles were eligible for inclusion. The highest pooled odds ratio (OR) was found for combined mechanical exposures [OR 1.7, 95% confidence interval (CI) 1.4-2.0], non-neutral postures (OR 1.7, 95% CI 1.4-2.1), lifting/carrying loads (OR 1.6, 95% CI 1.3-1.9), and climbing stairs (OR 1.6, 95% CI 1.1-2.2). The range of pooled OR for the remaining mechanical exposures (eg, standing, walking, kneeling, squatting, and sitting) was 0.6-1.6. Grading the quality of evidence, a moderate level of evidence was found for the combined mechanical exposures and for lifting/carrying loads. The remaining exposure categories were graded as having either low or very low levels of evidence.

Conclusions: Considerable heterogeneity was observed across the included studies, and high-quality literature using objective exposure measurements is warranted. Despite various limitations affecting the comparability, occupational mechanical exposures seem to influence the likelihood of developing hip osteoarthritis.

Figure 1

Flowchart of the study inclusion

Figure 2

Forest plot of exposure to lifting/carrying loads. Notes: adjusted variables (ASBLI) = age, sex, body mass index, leisure time activities, and previous injuries in lower extremities. + others refer to adjusting for other confounding factors besides the ASBLI-factors. [kg=kilograms; NS=not specified; x=times; OR=odds ratio.] * Allen 2010: OR calculated based on prevalence of distribution between groups (table 4 in the study). ** Jacobsson 1987: OR calculated based on numbers of participants (table 1 in the study). ^ Numbers in brackets states numbers of exposed persons with hip OA and numbers of exposed references, respectively. ^^ Numbers in brackets states numbers of unexposed persons with hip OA and numbers of unexposed references, respectively.

Figure 3

Forest plot of combined mechanical exposures. Notes: adjusted variables (ASBLI) = age, sex, body mass index, leisure time activities, and previous injuries in lower extremities. + others refer to adjusting for other confounding factors besides the ASBLI-factors. [kg=kilograms; NS=not specified; x=times; OR=odds ratio.] * Allen 2010: OR calculated based on prevalence of distribution between groups (table 4 in the study). ** Jacobsson 1987: OR calculated based on numbers of participants (table 1 in the study). ^ Numbers in brackets states numbers of exposed persons with hip OA and numbers of exposed references, respectively. ^^ Numbers in brackets states numbers of unexposed persons with hip OA and numbers of unexposed references, respectively.