HW6

Write a .do file that performs the tasks described below. Your .do file must be called hw2.lastname.firstname.do. Make sure your script will run on our machines by handling filepath ambiguity in your script. Do not submit your log files as part of the assignment.

Use the dataset pra_hist.dta and hosp.dta to perform the required tasks.

global repo https://github.com/jhustata/basic/raw/main/

Questions

Context : You are conducting a study that examines the regional variation in the distribution of panel- reactive antibody (PRA). You recruited 73 patients (px_id = 1, …., 73 ) from 10 hospitals (hosp_id=1, …,10) in 3 regions (region=A, B, C, … ), and measured PRA 3 times: visit 1, visit 2, and visit 3. You hear that the organization that funds your research plans to extend the funding for several more visits (visit 4, visit 5, …, visit N). Since you do not know how many more visits there will be, you decide to write a .do file that can work regardless of how many visits the dataset has.

Codebook

Variable	Description	Values/Range
pra_hist.dta
hosp_id	Hospital ID	Integers: 1 – 10
px_id	Patient ID	Integers: 1 – 94
visit_id	Visit ID	Integers: 1 – N 1 indicates the first visit. K indicates the K-th visit.
pra	PRA value at the visit	Integers: 0 – 100
hosp.dta
hosp_id	Hospital ID	Integers: 1 – 10
Region	Region	Alphabets

Note: to uniquely identify a patient you’d have to specify both hospital ID and patient ID. In other words, patients in different hospitals may have the same Patient ID

i) Load pra_hist.dta. Print a table as shown below, which displays the number of patients with a non-missing PRA value at each visit. N and XX should be replaced with the correct values from the dataset. (Hint: how do you write a forvalue loop for all values of visit_id?)

use "${repo}pra_hist", clear

Question 1.i)
Visit 	Count
1 			XX
2 			XX
		⋮
[omitted, but your .do file should display all variables]
		⋮
N 			XX

ii) Create a new variable peak_pra, which contains the maximum value of PRA within each participant. Print the median (IQR) of peak_pra across the patients as shown below. XX.X should be replaced with the correct values from the dataset and formatted with one digit after the decimal point (e.g., 12.0 ). (Hint: each patient must be counted only once when calculating the median and IQR.)

Question 1.ii): The median (IQR) of peak_pra is xx.x (xx.x-xx.x).

iii) Another dataset provided to you, hosp.dta, has information on which region each hospital is located in. Use the merge command to merge the current dataset in memory with hosp.dta without altering the number of observations in memory (see week 3 Section 3.3 for syntax or week 4 Section 4.2 for notes during a lecture session). Use the command list to list the ID of the patient with the highest peak_pra value for each region as shown below.

use "${repo}hosp", clear

XX should be replaced with the correct values from the dataset. If there are ties (i.e., multiple patients with the highest value), print all tied patients. If region C has ties (while A and B does not), the table will look like below.

+------------------------------------+
| region 	px_id 	peak_pra     |
|------------------------------------|
| A  	        XXXX    XXXX         |
|------------------------------------|
| B  	        XXXX    XXXX         |
|------------------------------------|
| C 	        XXXX    XXXX         |
| C  	        XXXX    XXXX         |
+------------------------------------+

Hint: your list command should look like this

list region px_id peak_pra [insert your code here], sepby(region) noobs

.