BOX 8-1

Experimental and Observational Studies

Experimental Studies Observational Studies
Randomized controlled trials With a control or comparison group:
Community trials    
Lab trials Analytic study
        Case control study
        Cohort study
            Without a control or comparison group:
        Descriptive study
        Correlational study
        Case series
        Case report
        Cross-sectional study

Randomized Controlled Trials

There is much disagreement about whether RCTs are needed for telemedicine. The strengths of RCTs include the randomization and the fact that they are typically prospective studies. One of the main goals of RCTs is to eliminate, or at least minimize, the different types of biases. Generally, RCTs seek to falsify a hypothesis (rather than confirm). Also, RCTs allow for meta-analysis because of the quantitative data that are collected. Weaknesses include that RCTs are expensive and time consuming, and randomization can be impractical. There may be ethical issues related to withholding a potentially beneficial treatment. For telemedicine, a double-blind study is nearly impossible, which may or may not be important.

Cohort Studies

Cohort study strengths include that the same characteristic is measured in two different groups. Typically, the groups differ in only one parameter— for telemedicine this would be the use of the technology versus traditional care. Eligibility and outcome assessments are usually standardized. The weaknesses are that these studies are observational, and they are often not randomized. For example, patients may be placed into a group based on a characteristic such as the presence of Internet connectivity in their homes, which may introduce some bias.

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