DE LA SALLE HEALTH SCIENCES INSTITUTE COLLEGE OF MEDICINE DEPARTMENT OF FAMILY AND COMMUNITY MEDICINE CM2 SY 2011-2012
OUTPUT 4: SAMPLING METHOD I. Group 1A, Dr. Jovilia M. Abong II. Research Question: Among students aged 13-14 with allergic rhinitis of selected schools in Dasmarias, Cavite, will exposure to air-conditioned school rooms affect the severity of their allergic rhinitis? General Objective: To determine if the exposure to the air-conditioning system affects the severity of allergic rhinitis in high school students aged 13-14, of selected schools in Dasmarias, Cavite. Specific Objectives: 1. To identify the prevalence of allergic rhinitis among high school students, aged 13-14, of selected schools in of Dasmarias, Cavite based on their exposure to air-conditioned rooms. 2. To identify the prevalence of allergic rhinitis among high school students, aged 13-14, of selected schools in Dasmarias, Cavite based on their exposure to non-air-conditioned classrooms. 3. To determine the severity of allergic rhinitis according to ARIA classifications. 4. To identify the risk factors of allergic rhinitis present in the classroom or school, such as pollen, molds, and cockroaches. 5. To determine the number of hours exposed to the classroom with or without air-conditioning system according to ARIA classifications. 6. Compare the severity of allergic rhinitis in students who are exposed to air-conditioned classrooms and those who are not exposed to air-conditioned classrooms. III. Research Design: Cross-Sectional Study IV. Definition of: 1. Study Population: Students aged 13-14 years old of selected high schools in Dasmarias, Cavite 2. Sample Population: Students aged 13-14 years old of selected high schools in Dasmarias, Cavite with allergic rhinitis. 3. Sampling Frame: List of Schools in Dasmarias, Cavite 4. Sampling Unit: Two selected schools 5. Elementary Unit: Student, 13-14 years of age with allergic rhinitis 1
V. Selection of: 1. Subjects
This study will be conducted using Stratified Random Sampling to select the subjects. In doing so, the list of schools in Dasmarias, Cavite will be obtained from Municipal Hall. Then, the schools will be divided into two strata, one having air-conditioned classrooms and the latter without an air-conditioning system. One school will be chosen to represent each group. Then, a letter will be sent to the chosen schools asking permission for their involvement in the study. List of Schools in Dasmarinas, Cavite
School with Airconditioned classrooms
School without Airconditioned classrooms
1 Representative School
1 Representative School
Figure 1. Schematic Diagram of the Stratified Random Sampling to be employed in the study.
2. Cases
The cases for the study will be chosen by screening each subject using a questionnaire that follows the International Study of Asthma and Allergies in Childhood (ISAAC) guidelines. Figure 2 shows the step-by-step procedure of the screening process.
School with Air-conditioned classrooms Inspect room for presence of air-conditioning system Selection of Students using ISAAC questionnaire Have you ever had a problem with sneezing, or a runny, or blocked nose when you DID NOT have a cold or the flu?
NO
YES
In the past 12 months, have you had a problem with sneezing, or a runny, or blocked nose when you DID NOT have a cold or the flu?
NO
Have you ever had hay fever?
YES
Interpretation
NO
Interpretation
YES
In the past 12 months, has this nose problem been accompanied by itchy-watery eyes?
NO
Interpretation
YES
In which of the past 12 months did this nose problem occur? (Please tick any which apply)
In the past 12 months, how much did this nose problem interfere with your daily activities?
Not at all A little A moderate amount A lot Seasonal rhinitis Perennial rhinitis CASE GROUP: Students 13-14 years old with confirmed AR with exposure to air condition
Figure 2. Schematic diagram of the selection of cases to be involved in the study. 3. Control The control group, who will have no exposure to air-conditioning system in the classroom, will also be chosen by screening each student with the same questionnaire. Based on the results, only those with allergic rhinitis will be chosen as the subjects for the study. The selected students are those who experience sneezing or a runny or blocked nose when they do not have a cold or flu. They are also those who experience such symptoms in the past 12 months, their symptoms are accompanied by itchy-watery eyes, and if such symptoms interfere with their daily activities. Those who have experienced hay fever before will also be selected for the studys control group. Figure 3 illustrates the screening procedure and is seen as follows:
Figure 3. Schematic diagram of the selection of controls to be included in the study.
