Gender roles and physical function in old age

Background: Gender differences in mobility disability among older adults are not well understood. Studies have focused on the biological differences between men and women, but not on the mobility differences due to interrelationships of sex and gender. The associations between masculinity, and femininity on physical function in old age have never been examined. Objective: The main objective of this dissertation is to study the relationships between physical function and gender roles in old age. To accomplish this objective, I have: 1) assessed the psychometric properties and construct validity of the 12-items short form Bem Sex Roles Inventory (BSRI), 2) examined the cross-sectional associations between BSRI and mobility and physical performance, and 3) examined mediating pathways between BSRI and physical performance.  Methods: A total of 2004 community-dwelling older adults from the International Mobility in Aging Study (IMIAS) aged 65 to 74 years were recruited in Natal (Brazil), Manizales (Colombia), Tirana (Albania), Kingston (Ontario, Canada), and Saint-Hyacinthe (Quebec, Canada). Two aspects of mobility loss will be assessed in this dissertation: first, Mobility disability is a self-reported measure of the difficulty to walk half a mile or climb one flight of stairs without assistance. Second, poor physical function or performance of the lower extremities which is assessed by an objective tool and defined as inability to perform physical action in the manner considered normal in the short physical performance battery (SPPB). This battery includes three timed tests of lower extremity function: a hierarchical test of standing balance, a four-meter walk, and five repetitive chair stands.  To assess the validity of BSRI in old age as a measure of gender roles. The psychometric properties of the 12- items short form BSRI were assessed by means of exploratory (EFA) and confirmatory factor analysis (CFA). To assess the cross-sectional associations between gender roles and both measures of mobility loss, I used Poisson regression analysis to estimate prevalence rate ratios of gender role types using the androgynous type as reference category. To calculate the incidence of poor physical performance after two years of follow up, Poisson regression was conducted for the estimation of relative risks. Body mass index, smoking, alcohol consumption, physical activity, chronic diseases, and depression were tested as potential mediators in the pathway between gender roles and physical performance in old age.  Finally, taking account the possible differences in associations between countries, I have conducted a meta-analysis to estimate overall effects of masculinity and femininity scores on physical performance based on five distinct studies representing each research site of IMIAS.  Results: The results of Exploratory Factor Analysis revealed a three-factor model. This model was further confirmed by CFA and compared with the original two-factor structure model. CFA results revealed that a two-factor solution (instrumentality-expressiveness) has satisfactory construct validity and superior fit to data compared to the three-factor solution. These factor analysis findings allowed to calculate scores of masculinity and femininity and classify participants into four categories according to gender roles: Masculine, feminine, androgynous and undifferentiated. Feminine and undifferentiated gender roles are independent risk factors associated with the prevalence of mobility disability and low physical performance in older adults. Consistent with cross sectional analysis, higher incidence of poor physical performance was observed among participants endorsing the feminine role or the undifferentiated role compared to the androgynous role. Higher masculinity but not femininity scores predicted good physical performance two years later. Gender roles predicted poor physical performance through statistically significant direct and indirect pathways. Cumulative smoking, BMI, physical activity, multimorbidity, and depression were serial mediators explaining the indirect effect of gender roles on physical performance. These intermediate behavioral and pathological pathways only partially mediated the observed associations. None of the potential serial mediators in the present study could completely account for the association between gender roles and physical performance. Conclusions:  Traditional gender roles are existent in the five research sites of IMIAS. Gender roles influence physical function in old age with a possible protective effect of androgyny in old age independent of biological sex. Gender roles influence health behaviors which in turn contribute to chronic conditions and faster decline of lower extremities physical function. This study adds to the scant literature on this topic and the findings obtained from this dissertation need to be confirmed by future longitudinal studies for the appropriate translation into public health actions.

Keyphrases: Masculinity, Femininity, Gender roles, Physical function, Aging