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Impact of California’s safe patient handling legislation on musculoskeletal injury prevention among nurses (Lee et al., 2019)

Review Guidelines

Absence of conflict of interest. 


Lee, S. J., Lee, J. H., & Harrison, R. (2019). “Impact of California’s safe patient handling legislation on musculoskeletal injury prevention among nurses.” American Journal of Industrial Medicine, 62(1), 50-58.


  • The study’s objective was to examine the impact of Safe Patient Handling (SPH) legislation in California (AB1136) on musculoskeletal injuries and prevention of these injuries among hospital nurses. 

  • The study used an interrupted time series design to compare musculoskeletal injuries before and after AB1136 SPH legislation using self-reported survey data from randomly selected California state registered nurses. 

  • The study found a negative relationship between SPH policies and programs and some types of musculoskeletal injuries, with lower rates of injuries following passage of the legislation. 

  • The quality of the causal evidence presented in this report is low because the authors did not observe outcomes for multiple periods before and after the passage of the legislation. This means we are not confident that the estimated effects are attributable to SPH legislation; other factors are likely to have contributed. 

Intervention Examined

Safe Patient Handling (SPH)

Features of the Intervention

This is a time series analysis of the impact of California's Safe Patient Handling (SPH) Act AB1136 on musculoskeletal injuries among RN's at two points in time. A survey was distributed to registered nurses in California in the years 2013 and 2016. The surveys were conducted via mail and contained a study information letter, a prepaid envelope to return the survey, and information about an option to complete the survey online. In 2016, the survey packet also included a mini-poster of results from the 2013 survey. The questionnaires included questions on demographic characteristics, workplace characteristics, SPH programs/practices, perceptions about SPH law and programs, work factors, risk perception, and work-related injuries and symptoms.   

The study sample included randomly-selected RN's in the state of California. A total of 281 RNs returned the survey during the 2016 data collection period and 254 selected RN’s returned the surveys in 2013. The RN's were chosen using stratified random sampling across nine regions in the state. The authors compared the outcomes of AB1136 on California RNs from 2013 to 2016. 

Study Sites

The study was conducted in California via an online or mail-in survey. 



  • Positive expectations of the legislation were at a higher level in 2016, with 33% believing policy and program changes in compliance with the CA SPH legislation were excellent or very good in 2016. 

Health and Safety

  • Major musculoskeletal symptoms were reported as reduced from 61% to 52%. This was especially true for symptoms in the lower back, neck, and hands/wrists.  

  • Musculoskeletal injury were similar at both points in time.   

  • The percentage of nurses with mechanical lifts in their unit was from 61% in 2013, and 80% in 2016. Similarly, the percentage with ceiling lifts increased from 12% to 24%. At the same time, reported frequency of lift use was static from 2013 to 2016.   


  • Knowledge of AB1136 increased from 56% in 2013 to 74% in 2016.  

  • 67% of nurses reported receiving SPH training in 2013 compared to 73% in 2016. 

Considerations for Interpreting the Findings

The study is focused on an analysis of self-reported data, which may have reporting biases. In addition, the percentage of respondents was relatively low. Specifically, the survey had a response rate of 24% in 2013 and 20% in 2016. Moreover, the comparison 2013 group was not a true control group since AB1136 was implemented in 2012. 

Causal Evidence Rating

We are not confident that the estimated effects are attributable to Safe Patient Handling (SPH); other factors are likely to have contributed. The outcome data were collected from two different groups at two different times. Because other factors might have changed at the same time (such as other hospital policies or training standards for nurses), differences in outcomes cannot be attributed solely to the intervention. In addition, the 2013 survey was conducted before the OSHA standards were developed, but one year after the SPH law became effective. As a result, the comparison is of an early implementation timepoint during which at least some sample members were likely to be aware of the intervention, even if their hospital had not yet implemented it. 

Reviewed by CLEAR

November 2022