A hospital-based nurse researcher at Hospital A conducts ...

[sarasara]

A hospital-based nurse researcher at Hospital A conducts experimental research on a rotating bed and its effect on prevention of pressure ulcers in hip fracture patients over 80 years of age with cognitive functional impairment.
 
  Because there are so few patients over 80 with fractured hips and cognitive functional impairment, and because the researcher anticipates problems with obtaining consent, a convenience sample is utilized and every patient who meets the criteria and consents is used in the study. The bed, although expensive, is found to be much more effective in preventing pressure ulcers in this population than is turning alone. The study is published. What are the implications of applying these findings, considering the researcher's use of a convenience sample? (Select all that apply.)
  a. The findings can be applied to similar patients who come to Hospital A, with the understanding that data collection will continue and represent a second study, since the research is unreplicated.
  b. The findings may be applicable to similar patients who come to Hospital B, but without replication, this use cannot be mandated in the research report.
  c. The rotating bed should not be used outside of Hospital A at all until a replication study is conducted.
  d. The study findings probably represent a type I error. It is doubtful that use of a rotating bed could produce significant findings with a convenience sample.
  e. The widespread use of the rotating bed has not been supported.
  f. Generalization is appropriate only extremely cautiously and in the same site in which the study was conducted, with tracking of subsequent data.

Question 2

Why are convenience samples used so frequently in nursing research? (Select all that apply.)
 
  a. More subjects consent if they can understand the sampling method.
  b. Obtaining a true random sample may be impossible.
  c. There is low risk of sampling bias.
  d. There are limited subjects available.
  e. Nonrandom sampling affects only generalizability, not study integrity.

[BUTTHOL369]

Answer to Question 1

ANS: A, B, E, F
In convenience sampling, any patients who meet the inclusion criteria are recruited for the study. Convenience sampling is considered a weak approach to sampling because it provides little opportunity to control for biases. Multiple biases may exist in convenience sampling; these biases range from minimal to serious. Additional studies with large convenience samples that have similar results would indicate the effectiveness of this intervention for practice. Studies with small convenience samples should be replicated to determine the accuracy of the findings and to increase the representation of the population studied. If findings are consistent over replications, then generalization to a larger group is possible.

Answer to Question 2

ANS: A, D, E
The majority of nursing studies use nonprobability sampling, especially convenience sampling, to select study samples. In conducting studies in nursing and other health disciplines, there are limited subjects available and often a random sample is not possible to obtain. Researchers often include any subjects willing to participate who meet the eligibility criteria. Nonrandom sampling affects only generalizability, not any other type of validity.