Philippines Pneumonia Study
Children in Bohol province in the Philippines were recruited into a longitudinal study of pneumonia incidence, over the period July 2001-December 2004. Recruitment occurred at attendance for their first vaccination at a health clinic in the recruitment catchment area, and children were followed until their second birthday or loss to follow-up. An outcome of interest was the occurrence of pneumonia, the most common cause of mortality in children in this area. The diagnostic definition of this was based on WHO criteria, itself based on clinical signs such as cough, fast breathing and chest indrawing.
The data are a sample of the 12,000 children recruited into the study.
PID Child ID Sequential Number from 1
Sex Sex of child Male
N_Children Number of children in the household Number
N_Siblings Number of live siblings of the child Number
Mother_Age Mother’s age at birth of child In years
Mother_Education Mother’s education Primary or High School
Mother_Employed Mother’s occupation Emp
Birth_Place Place of birth Home
Birth_Attendant Birth Attendant Physician Midwife
Vac_AgeMths Age at child’s first vaccination In completed months
Weight_kg Weight at first vaccination In kg
Weight_Group Weight group at first vaccination < 4.5 kg
4.5 – 5.4 kg
> = 5.5 kg
Vac_Season Season of first vaccination Winter: Months 12,1,2
Spring: Months 3,4,5
Summer: Months 6,7,8
Autumn: Months 9,10,11
Pneumonia Child experiences an event of WHO-defined pneumonia in his/her follow-up period (up to second birthday) 0=No
The research questions to be answered are as follows:
1. Is there an association between level of mother’s education and the incidence of pneumonia?
2. If yes, what is the strength of this association?
3. Is there an association between maternal unemployment and the incidence of pneumonia? What is the strength of this association?
4. As discussed in the lecture, stratified analysis is one method for assessing the potential for confounding. Conduct the following stratified analyses to test for confounders:
a. whether ‘number of children in the household’ is likely to confound the observed association between mothers education level and incidence of pneumonia.
b. Whether mother’s education level is likely to confound the observed association between maternal unemployment and incidence of pneumonia.
5. Discuss your findings and interpretations.
1. This task sheet
2. Data worksheet titled Pneumonia .xls
3. Supplement 1: Creating pivot tables in Excel.
4. Supplement 2: 95% CI and Adjusted RR
1. To assess the presence of an association between education and incidence of pneumonia, consider mothers with Primary / High school education as ‘exposed’; and mothers with College education as ‘unexposed’.
2. Using the data from the Pneumonia worksheet, set up a 2 x 2 table to calculate the incidence of pneumonia in exposed and non –exposed groups.
HINT: To extract the data for the 2 X 2 table, you could use the ‘Pivot table’ function in excel, following the instructions provided in Supplement 1. Remember to set it up according to the configuration below:
Mothers education Pneumonia
Primary / High school a b
College c d
Philippines Pneumonia Study