BSNC 5060: Module 8 Experimental and Quasiexperimental Design Activity Answer the questions that follow each description of an experimental or quasiexperimental study. 1. The objective of this study was to determine the outcomes of giving mammographic breast density (MBD) information to participants of a screening program. An experiment was conducted with a sample of 618 women aged 50 or greater with MBDs greater than 50% of breast volume. The intervention consisted of reporting the presence of MBD in the letter informing clients of their mammography results (sent along with an information pamphlet). Participants were randomly assigned to the 2 groups (intervention and control group). The intervention group received the MBD information in their letter. The control group did not receive the MBD information in their letter. All participants were tested on their understanding of breast density at the beginning of the study. In the post-test, more women in the intervention group understood density correctly and recognized it as a risk factor for breast cancer than did those in the control group. Although at the 4-week follow-up, more of those in the intervention group indicated they were “very likely” to have an annual clinical breast exam than did the controls, no differences were detected at 6 months. a. What type of design was used? Experimental pretest and post-test control group design (true experiment) b. What are the advantages of this design? The pretest lets the researcher compare the two groups on important antecedent variables before the intervention (treatment variable) begins. c. What are the disadvantages of this design? Minimal confidence that the intervention (treatment) group and the comparison (control) group were similar at the beginning of the study. 2. The purpose of this study was to examine caregiver outcomes among caregivers enrolled in a support program. Caregiver outcomes in regard to the following were measured: burden, quality of life, perceived health, opinion on institutionalization (just prior to client admission, at 2 weeks, at 2 months and 6 months after admission), and satisfaction with the program at three points after client admission. a. What type of design was used? Quasiexperimental time-series design b. Why is this a reasonable choice of design? 1 A control group was likely not feasible, since it would be very difficult to justify assigning some caregivers to a group which received no support. 3. The purpose of this study was to evaluate the effectiveness of interventions provided by a community mental health team in reducing stress in caregivers for persons with dementia. Following an initial multidisciplinary assessment, all caregivers of those with dementia were invited to participate; 26 caregivers consented and participated in all stages of data collection. Data were collected with the Caregiver Strain Index at initial assessment and again at 3 and 6 months. a. What type of design was used Quasiexperimental time series b. What are the advantages of this design This type of design is useful for determining trends. Data are collected for a baseline, the treatment is introduced and data are collected numerous times afterward to determine a change from the baseline. Each participant is compared to him- or herself over time. 2
