PUB315 Worksheet – Hypothesis Testing & T-test (60 points) Name: Samia Shawkat 1. (24 pts total) Read the paper by Seligman et al., 2015, “A pilot food bank intervention featuring diabetes-appropriate food improved glycemic control among clients in three states” (available on UBlearns) . Read the following abstract of this paper and answer questions below. ABSTRACT Food insecurity—defined as not having adequate quantity and quality of food at all times for all household members to have an active, healthy life—is a risk factor for poor diabetes control, yet few diabetes interventions address this important factor. Food pantries, which receive food from food banks and distribute it to clients in need, may be ideal sites for diabetes self-management support because they can provide free diabetes-appropriate food to people in low-income communities. Between February 2012 and March 2014, we enrolled 687 food pantry clients with diabetes in three states in a six-month pilot intervention that provided them with diabetes-appropriate food, blood sugar monitoring, primary care referral, and self-management support. Improvements were seen in pre-post analyses of glycemic control (hemoglobin A1c decreased from 8.11 percent to 7.96 percent), fruit and vegetable intake (which increased from 2.8 to 3.1 servings per day), self-efficacy, and medication adherence. Among participants with elevated HbA1c (at least 7.5 percent) at baseline, HbA1c improved from 9.52 percent to 9.04 percent. Although food pantries are nontraditional settings for diabetes support, this pilot study suggests a promising health promotion model for vulnerable populations. Policies supporting such interventions may be particularly effective because of food pantries’ food access and distribution capacity. (Seligman et al. Health Affairs. 2015. A pilot food bank intervention featuring diabetes-appropriate food improved glycemic control among clients in three states) a. (6 pts) In this study, the researchers were interested in examining the effect of the intervention on hemoglobin A1c (HbA1c) levels. What type of t-test should be conducted to examine the effect of the intervention on HbA1C? Explain why this type of t-test is appropriate in this case. b. (6 pts) What is the null hypothesis (H0) and alternative hypothesis (Ha) for comparing the HbA1c before and after the pilot food bank intervention? c. (6 pts) Define P value. Assume a significance level α = 0.05. Given a P value < 0.01, would the result be considered statistically significant? Do you reject the null hypothesis or not? Provide a brief explanation. d. (6 pts) Results of the t-test are shown below (***Indicates P < 0.01 in the table). At the 5% significance level, how do you interpret the result of this t-test for HbA1c levels? Based on results of the study, what would you conclude about the effect of the intervention on glycemic control?