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Inferential Methods (cont'd). Large dependent samples - McNemar's test (chi-square) Small dependent samples - McNemar's test (binomial). Matched Dichotomous Data. In some studies, we make comparisons of proportions across samples which are dependent.E.g. Cross-over studies- Relief of head
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1. Comparing Two ProportionsUsing Dependent Samples(p1 vs. p2)
2. Inferential Methods (cont’d) Large dependent samples - McNemar’s test (chi-square)
Small dependent samples - McNemar’s test (binomial)
3. Matched Dichotomous Data In some studies, we make comparisons of proportions across samples which are dependent.
E.g. Cross-over studies
- Relief of headaches using Drug A vs. Drug B
- Subject receives both treatments in random order
E.g. Treating ear infections
- randomly assign a one of two treatments to each ear
E.g. Infection status before and after treatment
4. Example 1: Effect of Disinfectant Use on Acute Cutaneous Complications (ACCs) During Insulin Pump Treatment A study examined the effect of disinfectant use on acute cutaneous complications (ACC’s) during insulin-pump treatment. At the time of the initial exam, 70.0% of 40 diabetic patients with insulin pumps had ACC’s at the needle insertion site. After use of a disinfectant on the skin before needle insertion for two to four weeks, 27.5% of the patients had ACC’s at the needle insertion site.
5. Example 1: Effect of Disinfectant Use on Acute Cutaneous Complications (ACCs) During Insulin Pump Treatment The data here is matched because we are examining infection status before and after regular disinfectant use at the injection site. We can create the data table as shown below