IHHP phases & methods
IHHP has a 3-phase design, lasting a total of 5-6 years.
This is a research-executive project consisting of a number of research studies before and after interventions, a number of cross-sectional surveys prior to interventions to evaluate the existing situation, during intervention and after intervention involving similar samples from the same society. Every stage of the program will be implemented in five years (stage I: one year, stage II: 3-4 years, stage III: one year, Final stage: one year-final analysis)
Studies concerning present situation analysis and population diagnosis conducted in intervention and reference communities (one year).
Phase I: Assessment of the existing situation
Initially, sample of each of the four studies are selected. The prevalence of risk factors is determined by standardized MONICA questionnaire and blood tests; the prevalence of coronary diseases by using standardized Rose questionnaire, electrocardiography and the Minnesota coding system, and the incidence of coronary diseases by following up samples, and extracting data from official statistics and records in cemeteries and Public Data Registry Organization
People's knowledge, attitude and practice toward NCD are determined based on the number of subjects in the samples, sex and age.
Rose questionnaire is filled and electrocardiography is conducted only for over-35 subjects.
Two intervention counties (Isfahan and Najaf-Abad) and a reference area (Arak), all located in central Iran, are included in the study. According to the 2000 National Census, the population was 1,895,856 in Isfahan and 275,084 in Najaf-Abad- a county neighboring Isfahan. Arak, located 375 km North-West to Isfahan with a population of 668,531 was selected as a reference area because of socioeconomic, demographic and health profile similarities to the intervention areas. The intervention program includes mass media campaigns and healthy policies targeted to the general populations in urban and rural areas in the intervention communities, and specific intervention actions targeted to women, children, adolescents, workers, the elderly, high risk groups (i.e., people with at least one risk factor or with symptomatic disease), and health professionals including physicians, nurses, health workers and health volunteers. Arak is monitored for evaluation purposes but does not receive interventions.
A number of trained interviewers were selected by the Deputy for Health and approved by authorities in the Center for Medical Education Development.
Physical examinations were conducted by trained physicians and laboratory tests including FBS, 2hpp, TC, HDL, LDL, TG, CRP and CBC were administered. All tests (except CBC) were conducted at the central laboratory of Isfahan Cardiovascular Research Center (ICRC), which is under quality control by Saint Rafael University, Leuven, Belgium. All electrocardiographs were also sent to ICRC.
The scientific committee headquarters are based in Isfahan Cardiovascular Research Center and supervise the processes whereby the questionnaires are filled. All stages of the implementation of this phase and other phases in the program are included in the program chart (Appendix). The first stage will last between 6 months and one year.
The intervention phase includes: Ten big integrated community-based interventional projects (currently underway in intervention areas). The coordinating committee is charged with prevention of replication or interference of interventional projects. This phase lasts 4-5 years.
Phase II (Intervention)
Implementation of this stage is based on education (education of the general population and high-risk individuals).
The intervention principles are based on two strategies, namely population and high-risk strategies (prevention strategies for high-risk individuals).
1- population strategies
These strategies are usually implemented via public education programs, e.g. educational films on ways of preventing cardiovascular diseases, posters. Pamphlets, face-to-face educational programs in the city by health volunteers, and by health assistants in villages who are trained with simple language.
These programs are also implemented for provincial education authorities (to encourage prevention from childhood) and industrial health officials in factories and institutions.
2- Strategy for prevention and control of risk factors in high-risk individuals (who already suffer from NCD or have at least one risk factor)
In this method, health volunteers or health assistants are trained with simply-worded educational models to refer patients to general practitioners. GPs are trained to use diagnostic and therapeutic algorithms to control risk factors in high-risk patients.
Risk factors will be explained with simple language.
The personnel involved in implementation of this strategy are health assistants in villages and health volunteers in cities. General physicians implement strategies for high-risk individuals in collaboration with other bodies, such as the Education Organization, Radio and Television Broadcasting Service, factories, institutions, etc. The target population consists of the population covered by health center No. 2 in the provincial cities of Isfahan and Najafabad.
To prevent time wastage, health volunteers, health assistants and general physicians are trained simultaneously with the implementation of the first phase of the program, to facilitate the start of interventions immediately following the first phase of the program.
Post-situation analysis and repeating all of the studies of the first phase and other follow-up studies, both in intervention and references areas on independent samples (one year).
Phase III (post-intervention assessment)
At this stage, all cross-sectional surveys on the prevalence of risk factors, prevalence of disease, awareness and practice of people and health personnel, mortality and morbidity following disease will be studied.
This study will be conducted on new samples from the society which has been studied in the initial phase of the program. Such studies may be conducted at other junctures, in addition to the last phase of the program. For instance, the project to assess knowledge and practice can be conducted one year after the intervention phase.
The prevalence of risk factors will be assessed after two years, and the prevalence of disease and mortality rate will be evaluated (providing that the program budget is increased) in the final year of the program.
The questionnaires and instruments used in the third phase are the same as in phase one. This phase will be conducted simultaneously in the provincial cities of Isfahan, Najafabad, and Arak.
Data collection and statistical analysis
All of the collected data in different phases of the program will be transferred to the headquarters for collecting data at Isfahan Cardiovascular Research Center and inputted into computers.
Statistical analysis of data from the first phase will be conducted simultaneously with the implementation of the second phase (intervention). Statistical tests used in analysis of data from the first and third phases of the program include odds variance analysis, different forms of regression, death ratio, calculation of death ratio, disease incidence (number/10000, or 100000), etc.