Participation Rates, Quality of Sampling Frames and Sampling Fractions in the MONICA Surveys

Appendix 1c

(See Sections 3.3 and 6.2 and Appendices 1a and 1b.)

Please complete this form for each of your reporting units and return to the MDC so that it is received there by 31 September 1995.

SAMPLE SIZE IN THE FINAL MONICA SURVEY

1. MCC name:____________________________________ Code: |____|____|
2. Reporting unit name: _____________________________ Code: |____|____|
3. Please complete the numbers of subjects in the cells of the following table.
(See instructions overleaf.)
  Men
  25-34     35-44     45-54     55-64     25-64     35-64  
A. Original sample size            
B. Not eligible            
C. Eligible sample size   C=A-B            
D. Non-responders            
E. Non-responders not possible to contact            
F. Responders   F=C-D            
G. Participation rate I   G=100×F/C            
H. Participation rate II  H=100×F/(C-E)            

 

  Women
  25-34     35-44     45-54     55-64     25-64     35-64  
A. Original sample size            
B. Not eligible            
C. Eligible sample size   C=A-B            
D. Non-responders            
E. Non-responders not possible to contact            
F. Responders   F=C-D            
G. Participation rate I   G=100×F/C            
H. Participation rate II  H=100×F/(C-E)            
yes no
4. Was your definition of eligibility to the sample the same as in MONICA Manual (see overleaf)? |___| |___|
5. Was the definition of eligibility the same as in the 1st survey? |___| |___|
6. Was the definition of eligibility the same as in the 2nd survey? |___| |___|
7. Comments (describe here also the differences if you coded "no" in question 4,5 or 6):





8. Name of person providing the information: ____________________________________________
Date: _____/_____/_____
  day    month  year

INSTRUCTIONS FOR COMPLETING TABLE 3 OF THE QUESTIONNAIRE

Use the same definition of age which you used when the sample was selected. Do not leave any cells blank. If the number for some cell is zero, print "0". If the information for some cell is not available, print "N.A." and explain in item 6.

A. Original sample size:
This is the number of subjects who were originally selected from the sampling frame. If you surveyed a wider age range (e.g. 25-74) for your local purposes. include here only the age range 25-64 (according to your local definition of age).
B. Not eligible:
These are individuals selected in the original sample who died or moved out of the reporting unit area before the survey examination (MONICA Manual*, pp.8-9).
C. Eligible sample size: C=A-B
D. Non-responders:
A non-responder is a person selected and eligible in the original sample who could not be found or contacted or a person who did not provide the questionnaire data at the clinic or during a home visit (MONICA Manual*, p.9).
E. Non-responders not possible to contact:
This is a subset of the non-responders for whom the item REASON of the non-responder data will be coded "1". These are subjects who were not possible to trace, e.g. letters returned with the notice: Address unknown, and further enquiries fail to establish the subject's whereabouts (MONICA Manual*, p.73). (Note that if it were known that the subject does not live in the reporting unit area, he or she would be "not eligible", and would not be included here.)
F. Responders: F=C-D
G. Participation rate I   G=100×F/C:
This is the usual participation rate reported in MONICA.
H. Participation rate II   H=100×F/(C-E):
In some MCCs, where accurate sampling frames are not available, the number of the non-responders not possible to contact is large, and many of such subjetcs are perhaps not living in the reporting unit area. Therefore, in such cases the Participation rate I may be an underestimate of the real participation rate. To show also an upper limit for the Participation rate, it has been suggested that we start to report Participation rate II together with Participation rate I. Participation rate II is informative only if considerable effort has been made to try to find out the whereabouts of those "not possible to contact".
For the first and the second survey, the two participation rates have been reported in the manuscript on trends in smoking, which will soon be circulated to the MCCs for their approval.

*MONICA Manual, March 1992, Part III, Section 1, MNM214.