Background: Although non-specific low back pain (LBP) is known to be multifactorial, studies from across the globe have documented their higher prevalence in nurses. This systematic review was conducted to ascertain whether this much-documented association constitutes a causal relationship, and whether there is a discernible threshold of exposures associated with this elevated risk.
Methods: PRISMA guidelines were followed and standard critical appraisal tools were applied. The outcome of interest was non-specific LBP or back injury; exposure was "performing nursing duties." Applicable studies, published in English during 1980-2012, were identified through database searches, screened against preset inclusion/exclusion criteria. Ergonomic assessments of nursing tasks were included along with epidemiological studies. Bradford Hill considerations for causation were utilized as a framework for discussing findings.
Findings: Of 987 studies identified, 89 qualified for inclusion, comprising 21 longitudinal, 36 cross-sectional analytic, 23 descriptive biomechanical/ergonomic, and 9 review studies. Overall studies showed that nursing activities conferred increased risk for, and were associated with back disorders regardless of nursing technique, personal characteristics, and non-work-related factors. Patient handling appears to confer the highest risk, but other nursing duties are also associated with elevated risk, and confound dose-response assessments related to patient handling alone. Associations were strong, consistent, temporally possible, plausible, coherent, and analogous to other exposure-outcomes, with risk estimates ranging from 1·2 to 5·5 depending on definitions. A threshold of nursing activities below which the risk of back disorders is not elevated has not been established.
Interpretation: Notwithstanding the bio-psycho-social nature of LBP, and complexities of studying this area, sufficient evidence exists of a causal relationship between nursing tasks and back disorders to warrant new policies.