Using the fitted regression model, estimate the average change in cry time for infants with severe pain versus those without severe pain, holding group constant. Provide a 95% confidence interval for this estimate
To estimate the average change in cry time for infants with severe pain versus those without severe pain, holding group constant, using a fitted regression model, you would need the following information:
1. Fitted Regression Model: First, you need a regression model that fits the data you have. This model would typically include predictor variables such as pain level, group, and cry time. The model should be fitted to the dataset containing information on infants' pain level, group, and cry time.
2. Variable Coding: The predictor variable for severe pain should be coded appropriately. Typically, binary coding is used, where infants with severe pain are assigned a value of 1, and infants without severe pain are assigned a value of 0.
Once you have the fitted regression model and the variable coding in place, you can proceed to estimate the average change in cry time for infants with severe pain versus those without severe pain, while holding the group constant. Here are the steps to follow:
1. Set the predictor variables: For estimating the average change in cry time, set the pain level to the value corresponding to severe pain (1) and keep the group constant (either 0 or 1, depending on which group you want to compare).
2. Calculate the predicted cry time: Use the regression model to calculate the predicted cry time for the given predictor variables.
3. Change in cry time: Now, set the pain level to the value corresponding to no severe pain (0) while keeping the group constant.
4. Calculate the predicted cry time: Again, use the regression model to calculate the predicted cry time for the new predictor variables.
5. Average change in cry time: Finally, subtract the predicted cry time for infants without severe pain from the predicted cry time for infants with severe pain to obtain the average change in cry time.
To obtain a 95% confidence interval for this estimate, you would typically use statistical software or packages that provide regression analysis. These tools automatically calculate the confidence interval based on the fitted regression model and provide the desired interval estimate.