Social inequalities in health accumulate throughout people's life trajectories and negatively impact the iraging. To this end, an instrument was developed to measure them. The method used was the design and validation of an instrument that initially consisted of 100 items. It underwent expert validation, reducing it to 77 items, and concluded with an exploratory factor analysis that resulted in 11 latent ítems to measure the phenomenon. The results indicate that the questionnaire consisted of 11 items that explore the structural and intermédiate determinants of social inequalities in health across the lifecourse: material conditions, education, employment, violence, and nutrition. The analysis shows psychometric adequacy (KMO = 0.64, explained variance 65.97%).
For discussion, the instrument allows for the exploration of social inequalities in health across the life course that impact aging and is applicable in clinical and community settings. The conclusión reached in this validation is that the instrument is brief, useful, and relevant for exploring the phenomenon and can be used in settings such as research, gerontological policy design, and interventions.
Social inequalities in Health, Life course, Social determinants, Gerontology
Social inequities in health are unfair and preventable disadvantages that negatively affect people throughout their lives [1,2]. Solar and Irwin [3] mention that inequities are measured by social determinants of health, which are structural (educational level, occupation, social class, gender, race/ethnicity) and intermediate (material conditions, psychosocial circumstances, behavioral and biological factors, access to the health system, and social cohesion). Inequities are not only seen in socioeconomic aspects, but also in gender, the individual's place of residence, and aspects such as ethnicity. These inequities accumulate From childhood to oldage, significantly impacting quality of life and aging [4,5]. From the life course approach, it is mentioned that what the individual experiences in each of the stages of life (childhood, youth, adulthood and old age) are trajectories that impact the mental, physical and social health of people [6,7]. If a person is immersed in inequalities in their life trajectory, they may present pathological aging; however, the World Health Organization and the Pan American Health Organization seek to help the population reach the echelon of healthy aging, which they define as the continuous process of optimizing opportunities, maintaining functional capacity and well-being, but as mentioned, it depends on the social determinants accumulated in their trajectory [8]. There is a need for a diagnostic instrument to help us explore this phenomenon, which is why the "Social Inequalities in Health Over the Life Course" questionnaire was developed. It was designed to collect data on life course trajectories and the impact of social inequalities on health in older adults. It was validated by experts in the field to ensure its contextual and theoretical relevance.
To structure and reduce its items, an exploratory factor analysis was conducted, allowing for the identification of latent items in the study population.
To develop and valídate an instrument to explore social inequities in health across the life course, using a rigorous methodological process of peer review and exploratory factor analysis to reduce the Number of items and assess the psychometric quality of the instrument.
This instrument was derived From the research "Social Inequity in Health Across the Life Course and Healthy Aging in Older Adults in the Municipality of Sayula, Jalisco, Mexico in 2022" [9]. As a first step, the expert review process was carried out. This methodological process is functional to evaluate each of the instrument's questions, identifying that they are clear, coherent, and appropriate, focused on the study's objective and the dimensions to be explored. The experts are specialists in the subject, and the purpose of this review is to improve the instrument, to have validity in its content, to optimize the interpretation of the data and have that scientific legitimacy [10]. Initially, the instrument had 100 questions to explore social inequities in health throughout the life course; after going through the expert review process, 77 items remained. In a second step, an exploratory factor analysis was carried out to reduce the Number of questions and that with these analyses, the phenomenon to be investigated could be explored. Exploratory factor analysisis a statistical technique that explores the structure of a set of questions and its objective is to search for latent factors that explain the correlations between questions. The technique seeks to ensure that instruments have a design and validation, ítem reduction, identification of factors or dimensions, and an assessment of psychometric quality. This tool is for the rigorous development of instruments in social sciences [11]. From the 77 items that were available after this factor analysis, the instrument was reduced to 11 items, which are presented in the following results section.
This research focused on developing a measurement instrument to explore social inequities in health, focusing on the life course, especially among older adults in a rural area of the State of Jalisco, Mexico. Items were taken from the Health, Well-being, and Aging Survey (SABE), the National Institute of Geography and Statistics [12], the Economic Commission for Latin America and the Caribbean (ECLAC), the National Health and Nutrition Survey (ENSANUT) [13], and Other authors such as Solar & Irwin; Oyola & De la Torre [14] and Peláez, et al. [15].
The instrument consisted of 77 items and explores social inequities in health, especially the structural determinants that include social position, education, occupation, income, gender, and ethnicity/race. Like wise, the intermédiate determinants comprised of the health system, material circumstances, social cohesion, psychosocial circumstances, and behavioral-biological factors, as mentioned, are given a life-course approach, encompassing childhood, youth, adulthood, and old age.
The instrument separated by determinant is seen in Table 1 and Table 2.
Table 1: Structural determinants of social inequalities in health over the life course. View Table 1
Table 2: Intermediate determinants of social inequalities in health over the life course. View Table 2
After developing this instrument, an exploratory factor analysis was conducted to identify latent factors. This analysis explores the set of common factors that explain the item responses [11].
This analysis is part of the multivariated imension reduction technique and operates under logical reduction, seeking to minimize the loss of information possible. That said, the reduction of this instrument continued to ensure that the information was not excessive or redundant during data collection [16].
Item distributions were reviewed as a preliminary step, as data reduction is still currently recommended [11]. When a relative frequency of responses below 5% was observed for an item, it was decided to eliminate it, given that it showed very high response homogeneity. The responses were dichotomized to divide the simple into two groups: subjects without the condition, and subjects with moderate and high conditions. Another step was to analyze the content validity of each ítem to determine a subset of items, from among all posible items, that would comprise the test version. The questions, i.e., their content, were examined for similarity or redundancy, ensuring that the questions were informed by theoretical knowledge of the field of study [16].
The questionnaire for this study was designed with indicators of social inequity in health across the life course, initially grouped into sub-indices for each life stage (childhood, adolescence, youth, adulthood, and old age). At the end of this process, the ítems to be submitted to the EFA were determined, and these were considered the social inequities in health across the life course in this study. In a first EFA, 38 components were tested, yielding a total explained variance of 11,958 for the first component and 8,111 for the second, for a cumulative variance of 20,068. Adding all 13 components, the total variance was 65,970. Seeking to increase the explained variance, 37 components were tested, performing a principal components analysis with Varimax rotation on the 37 items. A Kaiser-Meyer-Olk in sampling adequacy measure of 0.64 was found, indicating a value greater than 0.5, which indicates that factor analysis may be useful with the data.
The Bartlett test was significant at 1866.19; p < 0.05, indicating that factor analysis was useful for the data, and the variance in the first component was 12,203 and in the second 8,045, adding up to a cumulative explained variance of 20,248 between the first two components. The Percentage of explained variance of the 11 components was 65,975, so the latter result was chosen (Table 3).
Table 3: Exploratory factor analysis of social inequalities in health across the life course. View Table 3
After conducting this analysis, we arrive at an instrument composed of 11 items that explore social inequities in health across the life course (Table 4).
Table 4: Social inequities in health across the life course instrument. View Table 4
Developing and validating the instrument to explore social inequities in health across the life course from a gerontological perspective is a significant advance in this area of knowledge for a broader understanding of the social determinants that impact aging. The methodological procedure implemented in the expert review and factor analysis facilitates ensuring the contextual and theoretical relevance of the instrument and reducing the ítems without compromising the importance of the content. The results once again make it evident that individuals' life trajectories are marked by adverse socioeconomic factors, inequality in material resources and education, and exposure to situations that place individuals at a disadvantage or vulnerability, such as abuse, which has an alarming cumulative impact on the health of older adults. This result is consistent with what Elder [6] and CEPAL [7] mention, who state that experiences at each stage of the life course are alarming determinants of health status in old age. The development of this instrument with only 11 items aims to achieve efficiency and applicability, saving time when administering it. It can be applied in clinical or community settings, especially as was the case in our context, with a rural population where resources or time to administer the instruments are sometimes lacking. The instrument's diverse dimensions are comprehensive, giving it a gerontological approach, and it reveals the most latent dimensions such as material conditions, education, employment, nutrition, violence, etc.
One limitation is that our study was conducted in a rural area specifically among older adults, which may limit the generalization of the results to urban or socio cultural contexts. Although our final factor analysis achieved a significant reduction, there is a risk that it may have ignored significant dimensions that could benefit the analysis of social inequities in health across the life course in Other groups or regions.
Another limitation is that our study was cross-sectional, which prevents a causal relationship analysis between living conditions at each stage of the life course and Current health status. Someitems may be biased due to the interpretation given by the participating subjects, especially when the older population is involved, as they must recall experiences or events that occurred years ago.
The instrument developed and validated in this research is a break through in innovation because it is easy to apply and allows us to analyze and identify social inequities in health across the life course, especially in older adults. Its development involved a rigorous process, making it suitable for use by health professionals, decision-makers, researchers, or educators interested in researching or promoting equitable and healthy aging. The instrument not only visualizes the disadvantages in subjects' life trajectories, but also provides a support for evaluating and generating gerontological interventions with a comprehensive approach (biopsychosocial and spiritual), that are inclusive and fair in any context. It is recommended that it be used and applied to other rural and urban populations, and it would be advantageous to apply it in longitudinal studies to determine its validity and broadly investigate the trajectories of inequality and their impact on health and aging.