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In the WHO MONICA Project, data on cardiovascular risk factors were obtained through two or three surveys of independent random samples of the the MONICA populations (1). This data book provides detailed descriptive statistics on the survey data for each MONICA population.
In MONICA, data were collected from populations known as Reporting Units (RU). RU is an area delineated by a clear geographical boundary. Each MONICA Collaborating Centre (MCC) collects data for the age group 25-64 from one or more RUs. For the population surveys the age group 25-34 is optional, so that for some RUs survey data are available for the age group 35-64 only. The data book considers the Reporting Unit Aggregates (RUA) which are foreseen as potential candidates for units of analysis of the MONICA survey data. The RUAs, their abbreviations and RUs are listed in Table 1. Some of the RUAs have several versions distinguished by suffix a, b etc. Different combinations of the RUs may be used for analyses concerning single risk factor surveys, trends between the surveys and for analyses involving both risk factor and event registration data. The reason for the distinction is that some RUs of some RUAs were not included in every risk factor survey. Therefore, in AUS-PER, GER-BER, GER-BRE, GER-EGE, GER-KMS, GER-RDM, RUS-MOI and RUS-NOC there is an overlap of RUs included in the RUAs considered. Altogether 58 RUAs are considered.
The survey periods in the RUAs are given in Table 8 of the report on age, date of examination and survey periods in the MONICA surveys (2). The middle survey was optional and therefore not done by all MCCs. The final survey is missing from the RUAs which had to give up the study before its completion.
The sampling procedures varied between the MCCs, depending on which sampling frames were available and what was otherwise practical. A description of the sampling frames and procedures used is given in Table 1.2 of the report on participation rates, quality of sampling frames and sampling fractions in the MONICA Surveys (3).
Item response rates, defined as the proportion of those from whom data on blood pressure measurements are available among those who were selected and eligible for the sample, are described in Section 8 of the report on participation rates, quality of sampling frames and sampling fractions in the MONICA Surveys (3).
Standardized methods for data collection were defined for the MONICA Project, and particular attention was paid on training of the personnel involved in data collection and processing and on quality control. The level of standardization achieved and the quality of the data collected have been described in separate quality assessment reports. The ones relevant for this data book concern:
No data were excluded from this data book because of problems in the quality. Therefore, the quality assessment reports should be consulted before using the data presented.