The problem of the study
This study was conducted in a bid to determine whether rigorous nonrandomized studies (NRSs) can be used as an alternative or a complementary way of evaluating healthcare interventions. The commonly used method of evaluating healthcare interventions, viz. randomized controlled trials (RCTs) does not factor in the external validity of the variables under study. In addition, RCTs cannot be carried out on all healthcare interventions and the process is complex and unrepresentative. Therefore, these shortcomings underscore the importance of applying NRSs as an alternative method.
The importance of the problem
Health care delivery is shifting to evidence-based practice. However, for healthcare providers to adopt this revolutionary approach to service delivery, they need enough data that covers the different issues that arise during the process. Therefore, given the restrictive nature of RCTs, it was important to come up with a complementary method in a bid to have the relevant data for healthcare providers to make informed decisions about service delivery. This understanding underscores the importance of carrying out this study to determine the feasibility of NRSs.
Purpose of the study
The purpose of the study was to “test the feasibility of conducting rigorous, nonrandomized studies (NRSs) of healthcare interventions using existing clinical databases” (Harvey, Rowan, Harrison & Black, 2010, p. 86). The researchers accomplished this goal by “recruiting a large representative sample of hospitals, identifying eligible cases, matching cases to controls to achieve similar baseline characteristics, making meaningful comparisons of outcomes, and carrying out subgroup analyses” (Harvey et al., 2010, p. 86).
The main research question
The research question is not stated clearly. However, it could be what is the “feasibility of nesting a NRS in an existing, high quality clinical database in terms of being able to recruit a large representative sample of ICUs, identify eligible cases, adjust for differences in case-mix to enable meaningful comparisons of outcomes, and to conduct subgroup analyses” (Harvey et al., 2010, p. 87).
The study hypothesis
The hypothesis is not stated. However, the study could have two main hypotheses, viz.
- NRSs do not provide alternative methods of evaluating healthcare interventions.
- PACs reduce the mortality rate of critically ill patients
Study variables
The independent variable is the existence of clinical databases. On the other side, the dependent variable is the choice of the existing clinical databases used in the study. While the researchers could manipulate the choice of clinical databases to include in the study, they could not influence the existence of such databases. For instance, the researchers could decide to use clinical databases from a particular segment like teaching hospitals and ignore other forms of hospitals.
The theoretical framework
The researchers used a health belief theoretical framework in this study. Before the study was conducted, the effectiveness of using PAC on ICU patients had come under huge criticism. Studies carried on the issue had indicated that PAC increases mortality rate of critically ill patients. However, the long-held belief is that patients managed with PAC have better healthcare outcomes as compared to their counterparts who do not use this method. Therefore, the researchers wanted to use NRSs to determine the clinical effectiveness of using PAC in managing ICU patients.
Literature review
The available literature is very shallow and divided. While some scholars argue that CRTs offer the best healthcare-intervention evaluation mechanism, other researchers hold that this approach in limited in many ways. The proponents of RCT maintain that this method offers the “greatest internal validity for evaluating healthcare interventions” (Harvey et al., 2010, p. 87). On the other side, the proponents of NRSs hold that RCTs are limited in their applicability coupled with complexities in implementation. In addition, RCTs are known to assume external validity factors in the evaluation of healthcare interventions. Therefore, the researchers in this study wanted to determine the truth behind these opinions. In addition, PACs are known to increase mortality rates amongst critically ill patients. However, RCTs carried on the issue nullify these claims by insisting that mortality amongst patients using PACs and their counterparts not using them is almost the same. Therefore, the researchers in this study carried out a NRS on the PACs’ issue to determine whether the earlier RCTs carried on the issue are correct. In conclusion, the researchers found that RCT studies on PACs are erroneous because according to the NRS employed in this study, PACs are found to increase the mortality of critically ill patients.
Study design
The researchers utilized a nested case control (NCC) study design. In this design, “the outcomes of a cohort of patients managed with a PAC were compared with a matched cohort of patients managed without a PAC using data from the Case Mix Program Database (CMPD) run by the Intensive Care National Audit & Research Centre (ICNARC)” (Harvey et al., 2010, p. 87).
The source of the subjects
The subjects were taken from general ICUs taking part in the Case Mix Program Database (CMPD).
The studied organizations
The studied organizations included general ICUs taking part in the Case Mix Program Database (CMPD) in the United Kingdom. Specialist ICUs and high dependency units (HDUs) were not considered for the study.
Duration of the study
The study took 20 months from May 2003 to December 2004.
Reference
Harvey, S., Rowan, K., Harrison, D., & Black, N. (2010). Using clinical databases to evaluate healthcare interventions. International Journal of Technology Assessment in Health Care, 26(1), 86–94.