Particulars of Population-Based Quality of Life Research

The dissertation is devoted to the development and implementation of population-based research on health-related quality of life based on a representative sample of the Saint Petersburg population. The Russian version of the SF-36 General Health Questionnaire, which has undergone psychometric property verification, as well as a sociodemographic module developed with consideration of Russian ethno-linguistic specifics, were used in the work. The study was conducted in accordance with international recommendations and the protocol for population-based quality of life research.

The work makes it possible to obtain the first in Russia normative HRQOL indicators of the Saint Petersburg population, encompassing physical, psychological, and social functioning. Patterns of differences in HRQOL indicators between men and women, as well as their changes depending on age, have been identified. The obtained results can be used for population health monitoring, comparison of the condition of various patient groups with population norms, and assessment of the effectiveness of programs in the field of health care.

Relevance. The state of population health is one of the key criteria requiring comprehensive and thorough analysis [28]. Assessment of the health status of the population as a whole and its separate groups is an important element of the work of health care authorities in developed countries. This direction has also been identified as a priority in domestic medicine for the long-term period of 2000-2010 [32].

Research related to health-related quality of life (HRQOL) is a reliable and simple method for assessing the health and overall well-being of a person [19]. HRQOL allows for the assessment of a person's physical, psychological, and social well-being, with this assessment being conducted by the individual themselves. The study of HRQOL is a widely accepted in international practice highly informative, sensitive, and economical method for assessing the health status of both the population as a whole and separate social groups [43, 45, 53]. The method makes it possible to provide a quantitative assessment of the multi-component characteristics of human activity — his physical, psychological, and social functioning [52,63].

Data from population-based HRQOL studies, so-called population HRQOL norms, are of great value for various institutions of society [130, 146]. A norm in this context refers to the values of HRQOL indicators of the population of a given country or region. Normative HRQOL indicators exist in all developed countries of the world [112, 123,146].

Data on normative HRQOL indicators can be used in various spheres of public life [21, 43,45,53]:

• when comparing HRQOL indicators of certain population groups from various regions with the population norm;

• when conducting HRQOL monitoring of various strata of the population over the necessary observation period;

• when comparing HRQOL indicators of a specific group of patients with the population norm;

• when conducting a comprehensive assessment of the effectiveness of programs in the field of health care;

• when developing rehabilitation programs and social adaptation measures for various categories of the population.

Population-based HRQOL research is based on the general principles of HRQOL study and is conducted in accordance with the research protocol [132, 146]. The majority of population-based HRQOL studies are conducted under the auspices of the International Quality of Life Assessment (IQOLA) Project [76, 138]. Within the framework of the project, the structure of the population-based research protocol has been developed. The basis of the population-based HRQOL research protocol is the HRQOL assessment questionnaire. General questionnaires are used to obtain normative HRQOL indicators. Questionnaires that can be used to assess normative HRQOL indicators must be multidimensional, easy to complete, possess the necessary psychometric properties, and be applicable in international population-based and clinical studies [21]. The SF-36 General Health Questionnaire meets all of the stated requirements and is the most frequently used in population-based studies [144].

In accordance with the methodology of HRQOL research, before using a questionnaire in a new ethno-linguistic environment, it is necessary to verify its psychometric properties. As a rule, when using a questionnaire in a different cultural and linguistic environment, it is sufficient to evaluate its reliability and construct validity [73, 130]. A questionnaire can be used for population-based research if it demonstrates satisfactory characteristics of reliability and validity.

Another important component of population-based research is the development of a sociodemographic module that takes into account the specifics of the country in which the study is conducted [94, 104, 144]. The sociodemographic module includes questions of a substantive and demographic nature. Its structure and format are developed independently for each study. As a rule, the module is piloted during a pilot study. Based on the results of the pilot study, changes are made to its structure and the final version of the module is formed. The determination of the sample size of the population-based study and the assurance of its representativeness are also conducted at the stage of the pilot study.

Currently, population-based HRQOL studies are conducted in many countries of the world. Data on HRQOL indicators of men and women, HRQOL parameters in various age and social groups are used when conducting HRQOL monitoring of various groups of patients, when comparing HRQOL indicators of patients with the population norm, and also when conducting a comprehensive assessment of the effectiveness of medical programs and social adaptation measures for various categories of the population [21, 32].

To date, population-based HRQOL studies have not been conducted in Russia. Thus, obtaining HRQOL indicators for the population of Saint Petersburg is a relevant task. The development of a sociodemographic module and the verification of the suitability of the SF-36 General Health Questionnaire for use in population-based studies in Russia have significant practical importance. Scientific interest is represented by the comparative analysis of HRQOL parameters of men and women, as well as HRQOL indicators in various age groups of the Saint Petersburg population.

Research Objective

To study the features of population-based quality of life research using a representative sample of Saint Petersburg residents with the Russian version of the SF-36 General Health Questionnaire and to analyze the obtained results.

Research Tasks

1. To develop a protocol for population-based HRQOL research and to study the psychometric properties of the Russian version of the SF-36 General Health Questionnaire.

2. To determine the features of population-based HRQOL research on the model of a representative sample of Saint Petersburg residents.

3. To determine HRQOL indicators of the population in population-based research on the model of a representative sample of Saint Petersburg residents using the Russian version of the SF-36 General Health Questionnaire.

4. To identify patterns of changes in population HRQOL indicators associated with physical, psychological, and social functioning depending on sex and age.

Principal Provisions of the Dissertation for Defense

1. The Russian version of the SF-36 General Health Questionnaire, in combination with the developed sociodemographic module that reflects Russian ethno-linguistic specifics, makes it possible to conduct population-based HRQOL research in Russia.

2. There are differences in HRQOL indicators of men and women depending on the age of respondents. To a greater extent, they are manifested in the age range of 45-65 years. After 65 years, differences in HRQOL indicators between men and women are not determined.

3. In the general population, as the age of respondents increases, a reliable decrease in physical, mental, and social well-being occurs, with the maximum HRQOL values in the 20-24 age group and the minimum values after 65 years.

Scientific Novelty of the Research

For the first time in Russia, in accordance with international recommendations, a population-based HRQOL study was conducted using a representative sample of Saint Petersburg residents. Values of physical functioning, role physical functioning, vitality, psychological health, social functioning, pain, and general health parameters were obtained in a representative sample of Saint Petersburg residents. Differences in HRQOL indicators between men and women were identified and their age dynamics were studied. For the first time, it has been demonstrated that the Russian version of the SF-36 General Health Questionnaire possesses satisfactory psychometric properties and can be used in population-based HRQOL research in Russia.

Practical Significance of the Work and Its Implementation

The developed sociodemographic module can be applied when conducting population-based HRQOL research in Russia. The obtained normative HRQOL indicators of the Saint Petersburg population can be used in further population-based studies in Russia, as well as in clinical practice for comparing HRQOL parameters of patients with normative indicators.

Research results have been published in 13 printed works.

Volume and Structure of the Work

The dissertation consists of an introduction, 3 chapters, a conclusion, conclusions, practical recommendations, a bibliography, and 2 appendices. The work is presented on 101 pages of typed text, illustrated with 16 tables and 15 figures. The bibliography includes 34 domestic and 114 foreign sources.