The primary research question in the Coyne study addresses size and ownership type and whether they make a difference in efficiency. The extraneous variable that could have affected the relationship in this study is the comparison of a for-profit hospital and which can be the competing hospitals. According to the study, not-for-profit hospitals achieve higher efficiency levels than a government-owned hospital. Still, both government-owned and not-for-profit large hospitals report greater efficiency than smaller ones (Coyne et al., 2009). The study shows no comparison with the for-profit organizations that are similar in size in the Washington State area. Increased competition is associated with less efficiency, and the comparison could affect the relationship between the independent and dependent variables (Rosko, Wong, & Mutter, 2018).

The Messina studies research question asks the relationship between patient satisfaction and inpatient admission and whether it differs between teaching hospitals and non-teaching hospitals. Not all teaching and non-teaching hospitals are measured equally. Depending on the type and number of residency programs offered, a hospital is considered a major teaching or minor teaching hospital (Messina, Scotti, Caney, & Zipp, 2009). Major teaching hospitals provide more specialties, so they offer a variety of surgeries compared to minor hospitals. The comparison between major and minor can have an impact on admission thru discharge time. This could affect the relationship between the variables because major teaching hospitals can have patients with a longer hospital stay because they can be more critical.

Coyne, J. S., Richards, M. T., Short, R., Shultz, K., & Singh, S. CC. (2009). Hospital cost and efficiency: Do hospital size and ownership type really matter? Journal of Healthcare Management, 54(3), 163-176.

Messina, D. J., Scotti, D. J., Caney, R., & Zipp, G. P. (2009). The relationship between patient satisfaction and inpatient admissions across teaching and non-teaching hospitals. Journal of Healthcare Management, 54(3), 177-190.

Rosko, M., Wong, H. S., & Mutter, R. (2018). Characteristics of high-and low-efficiency hospitals. Medical Care Research & Review, 75(4), 454-478.