Question

Researchers randomly sampled 5880 Medicare beneficiaries from five states(patients were between the ages of 65 and 75). From that random sample, 567 patient records were excluded because the hospital refused to participate or because medical records were either missing or incomplete. The researchers reviewed medical records in order to collect the data:

Based on information in the passage, which aspect of the research design poses a methodological limitation?
A. The reliance upon medical records as a source of data
B. The lack of interview data with patients or providers
C. The percent from the sample that was excluded from the study
D. The number of patients who were included in the study

Answer 1

The methodological limitation in the research design is the percentage of the sample excluded from the study, which can introduce selection bias and affect the representativeness of the findings.

Step-by-step explanation:

The methodological limitation posed in the research design is C. The percent from the sample that was excluded from the study. The exclusion of 567 patient records (approximately 9.64% of the initial sample) due to hospitals' refusal to participate or incomplete medical records could introduce selection bias, potentially impacting the representativeness of the sample and thus the generalizability of the study's findings.

Convenience sampling, as indicated in the provided information relating to another researcher selecting patients he knew, is not random and can result in significant bias. A more appropriate sampling method would be to take a simple random sample from each group, possibly using a computer-generated list of random numbers to select patients.

For a study like the one involving medical doctors in a malpractice lawsuit, it is important to ensure that the sample is random and representative. The parameter of interest here would be the proportion of all medical doctors involved in malpractice lawsuits, while the statistic would be the proportion calculated from the random sample of 500 doctors selected.