Schoenfelder and Rubenstein set out to address the problem of the propensity for the elderly to experience falls and bring on further adverse consequences for themselves, not least of which is the shying away from exercise and other vigorous physical activity that would otherwise forestall accidental falls. This concern is relevant to the nursing profession because, at last count, there were already 1.6 million elderly persons in nursing homes around America (GAO, 2002); given the rapidly-aging “boomer” generation, this number can only continue to grow.
The research problem has salience partly because it is eminently researchable – both the intervention and the dependent variable are readily observable, after all – and partly because falls have the unfortunate consequence of causing tissue damage, disability, physical lassitude, and, by being weak and bedridden, a shortened lifespan.
The authors are explicit about their aim of testing to see whether an intervention based on walking and strengthening the ankle would have a measurable benefit in point of the dependent variable, “fall-proneness”. In that sense, the research was very narrowly focused as to both dependent and independent variables, the setting (resident nursing care), and the population (elderly residents 64 to 100 years). As such, there were no ethical concerns.
All told, Schoenfelder and Rubenstein cite 32 sources though one gains the impression that they were not particularly concerned about doing an exhaustive review of the field. Perhaps, Schoenfelder was satisfied that a pilot study she had completed and published in 2000 was enough of a baseline and set sufficient theoretical precedents. Importantly, the gap the two sought to address was the paucity of studies on elderly residents because it seems the “bulk of prior studies” was about community-dwelling elderly; as well, the authors claim that the combination of ankle strengthening and walking had never been reported.
The scale of the numbers is quite enough to suggest how sparse the literature review was. A quick electronic database search showed that no less than 326 studies were published in the field up to December 2003, by which time the authors would have been readying their analysis.
The truth is, gerontological concern about preventing falls is a fairly recent concern. An electronic search of the literature shows that the two authors gave short shrift to a pioneering effort by Kelly (1991); to their credit, they reach back to 1966 for a study by Graybiel and Fregly on cerebral ataxia. Nonetheless, Schoenfelder and Rubenstein did use their literature review to cite the adverse consequences of falls, importance as to prevalence (e.g. Gurwitz et al., 1994), to define the criterion variable (Tideiksaar, 1998), to assess the risk factors and validate the benefit of exercise. Still, one has to wonder at their thoroughness when the most recent citation was already all of three years old by the time they compiled the study results. Perhaps, the nature of the problem just does not warrant it but the team could not cite conflicting sources; at most, they disclosed a few that had insufficient explanatory power.
While not explicitly stating the framework, the authors cite the favorable results of the Schoenfelder pilot study (2000) that a program combining walking and ankle strengthening could improve “fall-related outcomes” and forestall physical deterioration in elderly nursing-home residents. This is completely logical, to the extent that continued physical activity is expected to produce such physiological benefits as improved circulation and muscle tone.
Hence, this 2004 effort advances the state of knowledge by explicitly investigating the benefits of the same intervention for several co-varying factors that are inversely related to falling risk: balance, ankle strength, and walking speed; decreasing risk of falling and fear of falling; and improving confidence in performing daily activities without falling (what the authors term “falls efficacy”). Sparse though it is, the review of the literature does cover all the ground needed to define the logic behind the directional hypotheses, i.e. the above falls-related outcomes would all improve after the introduction of the intervention.
The IV or intervention consisted of a) bilateral heel raises with progressive resistance training built-in, and b) walking for ten minutes building up to a brisk pace. The latter was measured with a stopwatch as the time required to walk six meters and therefore qualifies as interval level of measurement. The ability to do more repetitions with increasing ankle weights also qualifies as interval measurement. For both variables, every succeeding step in performance is equidistant from the previous one and requires, by implication, a similar improvement in physiological and physical capacity.
The DVs are all those listed as comprising “falls-related outcomes” in the prior section of this critique. While the cause-and-effect relationship between IV and DV’s as a group is crystal-clear, the authors suffer from an excess of zeal when they venture into covariates and psychological factors (e.g. “fear of falling”) when the effectiveness of the intervention could have been proven by behavioral and observable DV’s alone. Another pointless addition was that of matching experimental and control pairs according to their Risk Assessment for Falls Scale-II scores. In my opinion, the risk of expectation bias offset the benefit of matching; in any case, matching was not essential for the research design since the size of the sample afforded a degree of protection from the effects of variance in personal characteristics.
To their credit, the authors neutralized one extraneous variable – responding positively to continued attention because the intervention ran for six months – by according the control group an attention placebo.
The study covered 81 residents of 10 private, urban nursing homes in eastern Iowa. The age range was 65 to 100 years (mean: 84.1) and gender breakdown was skewed heavily toward women (62 participants). By itself, the gender ratio may mean nothing more than that women live longer than men. The matter of generalizability must consider the fact that sampling was effectively saturation coverage of all who could tolerate physical activity (hence, the authors did not address the adequacy of this sample size). The choice of just ten homes and of the locale itself must be considered convenience sampling and hence, a manifestation of sampling bias. The most rigorous thinking must acknowledge that the results may not even be projected to the rest of the state itself.
Other than obtaining physician consent that potential participants were not at risk for engaging in a regimen of short exercises (important because each exercise session lasted from 15 to 20 minutes and the entire intervention was scheduled for three months), it appears the researchers made no provision for voluntary participation. Hence, there was no need to account for the response rate.
On the whole, nonetheless, one must judge the research design as well thought out, systematic by setting measurable parameters for all the DV’s, and therefore appropriate to answer the research question posed. After accounting for all the controls and baseline measures taken, it is evident that the researchers had seen to remove all threats to validity.
Gurwitz, J.H., Sanchez-Cross, M.R., Eckler, M.A., & Matulis, J. (1994). The epidemiology of adverse and unexpected events in the long-term care setting. Journal of the American Geriatrics Society, 42, 33-38.
Kelley, M. M, Lipsitz, L. A, et al. (1991). Causes and correlates of recurrent falls in ambulatory frail elderly. Journal of Gerontology, 46 (4) M114-22.
U.S. General Accounting Office (2002). Nursing homes: Quality of care more related to staffing than spending.
Tideiksaar, R. (1998). Falls in older persons: Prevention and management. (2nd ed.). Baltimore: Health Professions Press.