NR 559 Week 4 Quantitative Research Critique Example

Quantitative Study Critique: The 2016 Randomized Trial of a Hospital Mobility Program for Older Veterans, Read for What the Comparison Group Received, Who Was Enrolled Against Who Is on My Unit, and Who Dropped Out

Student Name

College of Nursing, Chamberlain University

NR 559: Research Methods and Evidence-Based Practice for Professional Nursing Practice

Instructor Name

Month Day, Year

Quantitative Study Critique: The 2016 Randomized Trial of a Hospital Mobility Program for Older Veterans, Read for What the Comparison Group Received, Who Was Enrolled Against Who Is on My Unit, and Who Dropped Out

The Study

Brown et al. (2016) conducted a single-blind randomized clinical trial at a Veterans Affairs medical center in Birmingham, Alabama, enrolling patients admitted to medical wards between January 2010 and June 2011. One hundred patients aged 65 or older were randomly assigned either to a mobility program or to usual care. Outcomes were self-reported activities of daily living, measured with the Katz scale, and community mobility, measured with the Life-Space Assessment, which asks how far and how often a person moved in the preceding four weeks. Assessors were masked to group assignment. Follow-up was by telephone one month after discharge.

The Result

The groups did not differ in activities of daily living at any point. At one month after discharge, the Life-Space Assessment score was significantly higher in the mobility program group, 52.5, than in the usual care group, 41.6. The mobility group's score was similar to its score at admission, while the usual care group's score fell by about 10 points. The authors concluded that the program allowed patients to maintain their community mobility, and noted that lower life-space mobility is associated with increased risk of death, nursing home admission and functional decline.

The Comparison the Number Came From

A difference is only meaningful relative to what the comparison group received. In this trial, the usual care group received twice-daily visits from study staff, without assisted walking. That is a thoughtful design choice: it controls for the attention and social contact the mobility group received, so that the difference reflects walking rather than company. It also means the comparison was not simply "nothing." Usual care on the study wards presumably included whatever physical therapy and nursing encouragement those wards normally provided.

For my unit, the question is whether our usual care resembles the study's. On our unit, older patients receive physical therapy once a day at most and rarely walk otherwise. If our usual care provides less mobility than the study's usual care, the difference we might see from a walking program could be larger. If it provides more, the difference could be smaller. The study does not describe usual care in detail, which limits this comparison.

Who Was Enrolled, Against Who I Have

The eligible group was patients aged 65 or older, cognitively intact and able to walk two weeks before hospitalization. The enrolled patients had a mean age of 73.9 years; 97 of 100 were men; 19 were Black; and the median length of stay was three days.

Set beside the patients on my unit, three mismatches stand out. First, sex: nearly all participants were men, while more than half of our older patients are women. There is no strong reason to think walking would work differently in women, but the trial cannot show that it does. Second, cognition: the trial excluded patients with cognitive impairment, while a substantial share of our older patients have dementia or develop delirium, and they are often the ones kept in bed. Third, length of stay: a median of three days leaves little time for a program to act, while our older patients stay longer on average, which could allow more benefit or more decline.

The trial's findings therefore apply most directly to cognitively intact older adults with short stays. For our patients with dementia or long stays, the trial is suggestive but not conclusive.

Who Was Still There at the End

Eight of the 100 patients did not complete the study: six in the mobility group and two in the usual care group. That imbalance matters. If the six who left the mobility group were those who found the walking hard, the remaining mobility group may have been healthier than the group originally randomized, which would inflate the benefit. The abstract does not report reasons for loss or whether the analysis included all randomized patients. A reader should check the full article for an intention-to-treat analysis before relying on the result.

Size and Meaning of the Effect

A difference of about 11 points on the Life-Space Assessment is larger than the roughly 10-point decline seen in usual care, which the authors describe as clinically significant. Life-space mobility has been validated in community-dwelling older adults (Baker et al., 2003). With 100 participants, however, the estimate of the difference is imprecise, and the trial was not large enough to detect differences in less common outcomes such as falls, readmission or nursing home placement. The absence of an effect on daily activities could mean the program does not help them, or that the measure was not sensitive enough in patients who were largely independent at baseline.

Bias and Rigor Beyond the Headline

Several features of the design protect against bias. Randomization balanced the groups at baseline, and the authors reported no significant differences between them. Outcome assessors were masked to assignment, which reduces the risk that expectations shaped the telephone interviews. The attention control, twice-daily visits for the usual care group, reduces the chance that social contact rather than walking explains the difference. And the trial was registered, which allows readers to check that the reported outcomes were the planned ones.

Other features warrant caution. The participants could not be masked, since they knew whether they were being walked, and the outcomes were self-reported, so participants who valued the program might report more mobility. The trial was conducted at a single site, so the program's delivery reflects that hospital's staff and culture. And one month is a short follow-up; the benefit may grow, fade or persist over a longer period, which the trial cannot show.

What I Would Want to Know Next

Before recommending the program widely, I would want a larger trial including women and patients with mild cognitive impairment, with longer follow-up and falls as a measured outcome. In the meantime, the trial is strong enough to justify a carefully measured local program.

Verdict for My Unit

The trial is a well-designed test of whether assisted walking preserves community mobility in older veterans with short stays, and it found that it does. It is less informative about women, patients with cognitive impairment and longer stays, all common on my unit. It supports trying a walking program, with outcomes measured locally, rather than assuming the same effect. It also suggests which outcome to measure: mobility after discharge, not only daily activities. Evidence from observational studies that low hospital mobility is associated with poor outcomes (Brown et al., 2004) supports the importance of the question beyond this single trial.

References

Baker, P. S., Bodner, E. V., & Allman, R. M. (2003). Measuring life-space mobility in community-dwelling older adults. Journal of the American Geriatrics Society, 51(11), 1610-1614. https://doi.org/10.1046/j.1532-5415.2003.51512.x

Brown, C. J., Foley, K. T., Lowman, J. D., MacLennan, P. A., Razjouyan, J., Najafi, B., Locher, J., & Allman, R. M. (2016). Comparison of posthospitalization function and community mobility in hospital mobility program and usual care patients: A randomized clinical trial. JAMA Internal Medicine, 176(7), 921-927. https://doi.org/10.1001/jamainternmed.2016.1870

Brown, C. J., Friedkin, R. J., & Inouye, S. K. (2004). Prevalence and outcomes of low mobility in hospitalized older patients. Journal of the American Geriatrics Society, 52(8), 1263-1270. https://doi.org/10.1111/j.1532-5415.2004.52354.x