"Community-Based Health Promotion Program for Older Adults" is a great example of a paper on the health system. The essay aims to address a two-fold objective to wit: (1) to critically analyze the article; and (2) to identify the threats to internal and external validity and reliability. Wallace et al. (1998) conducted a pilot study to evaluate the feasibility and efficacy of delivering an integrated disability prevention intervention at a neighborhood senior center (M301). The authors employed a 6-month randomized clinical trial to which the experimental group received exercise intervention, nutrition counseling, and a home safety assessment while at-risk subjects received smoking and alcohol interventions.
The study population consisted of 750 randomly selected individuals age 65 years and older at the Northshore Senior Center in which 100 were randomized: 53 to the intervention group and 47 to the control group. Outcome variables included Medical Outcomes Study Short Form (SF-36) health survey, CES-Depression scale, bed days, and restricted-activity days. Wallace et al. (1998) concluded that a community-based disability-prevention program with supervised exercise may be effective to meet some of the Healthy People 2000 goals to enhance function in older adults (M305). Randomized controlled trials (RCTs) or experiments have a high degree of internal validity because of randomization done to different groups to rule out competing explanations (Polit & Beck, 2009, 246).
The study of Wallace et al. has no problem in establishing a temporal sequence as the authors created the independent variable (community-based health promotion program) and observe its outcome (feasibility and efficacy of the variable). Selection is another threat to internal validity. Although Wallace et al. randomly assigned samples into groups, differences in the groups being compared may exist and may not be equivalent.
History threat is also not a problem in RCTs and experimental designs as there are no external events stated in the study of Wallace et al. that could affect the dependent variable. In addition, the possible occurrence of a history threat may affect both groups in randomized controlled trials (Polit & Beck, 2009, 247). The study of Wallace et al. might face the internal validity threats of maturation and mortality/attrition. Maturation threat arises from processes occurring as a result of time (Polit & Beck, 2009, 247).
The study of Wallace et al. applied the same intervention done in the experiment group to the controlled group six months after; thus, Wallace et al. must have considered the progress that would occur in studying the feasibility and efficacy of delivering an integrated disability-prevention intervention at a neighborhood senior center. The mortality/attrition rate is also a problem. A 10% attrition rate in the study of Wallace et al. was fairly low but notice that 8 out of the 10 who dropout from the program was from the intervention group.
With this, a threat to internal validity related to mortality/attrition rate occurred because of the differences in the SF-36 social function subscale and not on the independent variable or the integrated disability-prevention intervention. The study of Wallace et al. has utilized interrater reliability, the comparison of ratings between two or more judges or groups to determine the degree of agreement in the scoring of the instrument (Polit & Beck, 2008, 456). By group-level comparisons, studies with reliability measures of. 80 or greater are highly desirable; in this case, the coefficient of. 08 reflects low reliability of measures.
This indicates why despite the efficacy of SF-36 subscales to determine decline, only the exercise regimen was viewed to have the most impacted health and functional health status as other risk factors such as alcohol misuse, smoking, poor nutrition, and presence of home safety hazards have low prevalence rate. Meanwhile, a threat to external validity also exists in the study as it has limited generalizability and might not hold true for different people, conditions, and settings.
The samples were not representative of the population because the majority of the participants are Whites and educated. The results of the study suggested that the community-based disability-prevention program featuring exercise regimen may be effective to meet ‘ some of the Healthy People 2000 goals and therefore, warrants attention in generalizing the results of the study to the ever-all older population of the United States. Besides, the setting is also limited to Northshore Senior Center and has made the study not representative of the general population.
Polit, D.F. & Beck, C.T. (2008). Assessing Measurement Quality in Quantitative Studies. Nursing Research: Generating and Assessing Evidence for Nursing Practice (8th ed.) (p. 449-473). Philadelphia: Lippincott Williams & Wilkins.
Polit, D.F. & Beck, C.T. (2009). Quantitative Research Design. Essentials of Nursing Research: Appraising Evidence for Nursing Practice (7th ed.) (p. 221-257). Philadelphia: Lippincott Williams & Wilkins.
Wallace, J. I. et al. (1998). Implementation and effectiveness of a community-based health promotion program for older adults. Journal of Gerontology, 53A (4), M301-M306.