Question 1: What is the logit of probability 0.75?
Question 2: Regress survival in next 6 months on comorbidities of the patients, age of patients, gender of patients and whether they participated in the medical foster home program. MFH is an intervention for nursing home patients. In this program, nursing home patients are diverted to a community home and health care services are delivered within the community home. The resident eats with the family and relies on the family members for socialization, food and comfort. It is called "foster" home because the family previously living in the community home is supposed to act like the resident's family. Enrollment in MFH is indicated by a variable MFH=1.
Survival is reported in two variables. One variable indicates survival in 6 months. Another reports days known to survive, if the patient has died and otherwise null. Thus a null value in this latter variable indicates the patient did not die.
CCS in these data refers to Clinical Classification System of Agency for Health Care Research and Quality. These data indicate the comorbidities of the patient. When null, it is assumed the patient did not have the comorbidity. When data are entered it is assumed that the patient had the comorbidity and the reported value is the first (maximum) or last (minimum) number of days till admission to either the nursing home or the MFH. Thus an entry of 20 under the minimum CCS indicates that from the most recent occurrence of the comorbidity till admission was 20 days. An entry of 400 under the Maximum CCS indicates that from the first time the comorbidity occurred till admission was 400 days. You choose what data (minimum, maximum, occurrence) is relevant for the analysis and you use what you think should be used. Keep in mind the possibility that for acute illness the most recent event may be predictive while for chronic illness the first occurrence may be predictive of cost.
The functional disabilities are probabilities that the patient has the disability. These probabilities are generated from the CCS diagnoses and demographics of the person.
Clean the data using SQL. There are a number of cases that repeat and should be deleted from the analysis. There are many null values. The treatment of null value changes with the type of variable. In some variables, null values indicate zero. In others they can be estimated from the mode. In still others, they should be treated as separate variable. In completing this assignment follow these steps:
Question 3: The following data provide the length of stay of patients seen by Dr. Smith (Variable Dr Smith=1) and his peer group (variable Dr. Smith = 0). Answer following questions:
Question 4: The following data provide the survival among cancer patients. The data provides 35 common comorbidities for patients who have or don't have stomach cancer. Use both logistic and ordinary regression to analyze these data and report the difference of the findings, in particular:
Report how the coefficients for the comorbidities of stomach cancer. How do these coefficients change across the two methods? Data►
Question 5: For this assignment you can use any statistical software you are familiar with or use R. You can also use MatchIt or other software designed to do propensity scoring. The objective is to find response to citalopram for patients with different types of depression. These data come from STAR*D experiment conducted by NIMH.
Question 6: The following problem was first created by Morgan and Harding and we have adjusted it to fit within health care. In this example, the outcome are length of stay in the hospital, the treatment is the clinician/his peer group and the strata are a mix of medical history and demographic variables that account for the pattern of self-selection into treatment. This mix have been divided into 3 strata: low, medium and high risk. What is the impact of clinician on length of stay, after removing confounding associated with severity of the patients' illness?
Solution by Morgan and Harding Read► Answer►
For additional information (not part of the required reading), please see the following links: