Results Summary

What was the research about?

People with a spinal cord injury, or SCI, can have different types of paralysis. With paraplegia, people can’t move their legs. With tetraplegia, people can’t move their arms and legs. Both types damage the nerves that control the bladder and usually cause problems with urination. People with SCI can manage bladder control in different ways.

In this study, the research team looked at four ways people with SCI use to control their bladder:

  • Intermittent catheter: Placing a catheter, a tube to drain urine, in the bladder several times a day and then removing it
  • Indwelling catheter: Leaving a catheter in the bladder
  • Voiding: Planning times to urinate or using a diaper to catch urine
  • Surgery: Having surgery to improve bladder function

The research team compared how these four ways affected people’s well-being and bladder function.

What were the results?

Of people in the study, 51 percent used intermittent catheters, 18 percent used indwelling catheters, 18 percent used voiding, and 13 percent had had surgery.

People with paraplegia had different results than people with tetraplegia.

People with paraplegia. Compared with people who used intermittent catheters, people who

  • Used indwelling catheters reported better bladder function and fewer problems with urine leaking and storage
  • Used voiding reported worse bladder function and more urine storage problems
  • Had previous surgery reported better bladder function, less incontinence, fewer problems with urine storage and bladder management such as worrying about having accidents, and more satisfaction with bladder function

Regardless of their treatment, people with paraplegia had similar reports of infections, kidney problems, bladder medicine use, or how bladder problems affected their lives.

People with tetraplegia. Compared with people who used intermittent catheters, people who

  • Used indwelling catheters reported better bladder function and fewer problems with bladder management, urine leaking, and storage
  • Used voiding reported worse bladder function and more problems with bladder management, urine leaking, and storage but reported fewer infections and kidney problems and less medicine use
  • Had previous surgery reported better bladder function, fewer problems with bladder management and urine storage, and higher satisfaction with bladder function

Regardless of their treatment, people with tetraplegia gave similar reports of how bladder problems affected their lives.

Who was in the study?

The study included 1,479 people with SCI from across the United States and Canada. Of these, 86 percent were white, 7 percent were African American, 1 percent were Asian, and 6 percent were other races; 6 percent were Hispanic. The average age was 45, and 60 percent were men. In addition, 54 percent had paraplegia, 43 percent had tetraplegia, and 3 percent had a different SCI.

What did the research team do?

The research team interviewed people at the start of the study and a year later. People also filled out surveys every three months for one year.

People with SCI, caregivers, doctors, and statisticians gave input on the study.

What were the limits of the study?

People with worse bladder problems may have been more likely to join the study in order to learn more about managing bladder problems. Results may differ for people with less severe bladder problems. The research team had planned to compare bladder function for people who did and didn’t have surgery during the study. These two groups had similar results, but because too few people had surgery, the team couldn’t say with confidence that surgery affected bladder function. 

Future research could enroll people in a study when they start using a new way to control their bladder and could include more people having surgery. Also, future research could explore using the study findings to support patients in making decisions that work best for them.

How can people use the results?

People with SCI and their doctors can use these results when considering how to manage bladder control after SCI.

Final Research Report

View this project's final research report.

Journal Citations

Related Journal Citations

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers asked that the researchers provide more clarity regarding some major limitations to the interpretability of the study results. Specifically, because this is an observational study, it can detect associations only, not cause and effect. Second, the reviewers noted that the study’s primary and secondary outcomes are highly correlated, given that three secondary outcomes are actually subdomains of one of the primary outcome measures. The researchers acknowledged the limitations in the text and added language related to these limitations in the discussion.
  • The reviewers asked for an explanation for why the study focused on the 12-month final endpoint rather than incorporating data from all time points. The researchers explained that they only analyzed treatment effects at the final time point because the study had far fewer participants than originally anticipated, limiting the interpretability of analyses that would take each time point into consideration. The researchers added text explaining their decisions.
  • The reviewers commented that the reported number of bladder management options evaluated was inconsistent, sometimes reporting three and sometimes four.  The reviewers also commented that how the researchers compared the options was not always clear. The researchers said that the confusion reflected the differences between their original proposal and how they accomplished the study’s objectives. The original funding application discussed only three treatment groups, but the researchers included four groups in the analysis. The researchers changed language throughout the report to more accurately reflect what they did.
  • The reviewers noted that the researchers stratified the analyses in the results section by whether participants were tetraplegic or paraplegic. However, they point out that the researchers did not state in advance any of their hypotheses or analysis plans relating to these subgroups. The researchers responded that they decided to stratify participants in this way only after their patient advisory group recommended it. They added text about the separation of participants into two groups including in the abstract. 

Conflict of Interest Disclosures

Project Information

Jeremy Myers, MD
University of Utah
Patient Reported Outcomes for Bladder Management Strategies in Spinal Cord Injury

Key Dates

April 2015
December 2019

Study Registration Information


Has Results
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Last updated: January 25, 2023