Factorial invariance and latent mean structure of questionnaires measuring social-cognitive determinants of physical activity among black and white adolescent girls.

BACKGROUND: We previously developed questionnaires based on contemporary theories to measure physical activity determinants among youth [Motl et al., Prev Med 2000; 31:584-94]. The present study examined the factorial invariance and latent mean structure of unidimensional models fit to the questionnaires measuring attitude, subjective norm, perceived behavioral control, and self-efficacy about physical activity among black and white adolescent girls. METHODS: Black (n = 896) and white (n = 823) girls in the 8th grade completed the questionnaires measuring attitude, subjective norm, perceived behavioral control, and self-efficacy about physical activity. The responses were subjected to analyses of factorial invariance and latent mean structure using confirmatory factor analysis with full-information maximum likelihood estimation in AMOS 4.0. RESULTS: The unidimensional models of the four questionnaires generally demonstrated invariance of the factor structure, factor loadings, and factor variance across race but not invariance of the variance-covariance matrices or item uniquenesses. The analyses of latent mean structure demonstrated that white girls had higher latent mean scores on the measures of attitude and self-efficacy than black girls; there were similar, but smaller, differences between white and black girls on the measures of subjective norm and perceived behavioral control. CONCLUSIONS: The questionnaires can be employed in interventions to test the mediating influences of attitude, subjective norm, perceived behavioral control, and self-efficacy on participation in physical activity by black and white adolescent girls.     

Measurement of perceived school climate for active travel in children

OBJECTIVES: To describe the development of an original scale that measures perceived school climate for active travel in fourth- and fifth-grade girls and boys. METHODS: The data were analyzed using confirmatory factor analysis (CFA) to provide evidence of factorial validity, factorial invariance, and construct validity. RESULTS: The CFA supported the fit of a 3-factor (encouragement, praise, and importance) correlated model for the school climate for active travel measure. This hierarchical model was invariant between sex and across a 7-month time period, and initial evidence for construct validity was provided. CONCLUSIONS: School climate for active travel is a measurable construct, and preliminary evidence suggests relationships with more support for active travel from friends and family.     

The children's DEBQ for assessment of restrained, emotional, and external eating in 7- to 12-year-old children

OBJECTIVE: Construct an age adapted version of the Dutch Eating Behaviour Questionnaire (DEBQ) for measurement of restrained, emotional and external eating in 7- to 12-year-old children: the DEBQ-C. METHOD: The DEBQ-C was constructed and tested for its reliability, factorial validity, factorial invariance for sex, overweight (BMI-status), and age, and correlations with measures for unhealthy life style in one sample (382 boys and 387 girls). In a second sample (252 boys and 263 girls) correlations were obtained with measures for body dissatisfaction and parental feeding styles. Single and multigroup confirmatory factor analyses were used. RESULTS: The fit measures for the three factor model and the factorial invariance models with respect to sex, BMI-status, and age were satisfactory. In the (sub) samples of the 7- to 12-year-olds Cronbach's alpha's ranged from .73 to .82 and there were satisfactory correlations (p < .01) with other measures. CONCLUSION: The DEBQ-C should provide a useful measure for young children's emerging dietary restraint and overeating tendencies. The low prevalence of emotional eating indicates that most young children show the natural reaction to emotional stressors (loss of appetite when feeling lonely, depressed or afraid) and that emotional (over) eating at this age is quite abnormal.     

Psychosocial correlates of physical activity in white and African-American girls.

PURPOSE: To evaluate the relative utility of the Theory of Reasoned Action (TRA) and the Theory of Planned Behavior (TPB) in explaining intentions and physical activity behavior in white and African-American eighth-grade girls. METHODS: One-thousand-thirty white and 1.114 African-American eighth-grade girls (mean age 13.6 +/- 0.7 years) from 31 middle schools in South Carolina completed a 3-day physical activity recall and a questionnaire assessing attitudes, subjective norms, perceived behavioral control, self-efficacy, and intentions related to regular participation in moderate-to-vigorous physical activity (MVPA). RESULTS: Among Whites, 17% of the variance in intentions was contributed by subjective norms and attitude, with intentions accounting for 8% of the variance in MVPA. The addition of perceived behavioral control and self-efficacy to the TRA significantly improved the prediction of intentions and MVPA accounting for 40% and 10% of the variance, respectively. Among African-Americans, subjective norms and attitude accounted for 13% of the variance in intentions, with intentions accounting for only 3% of the variance in MVPA. The addition of perceived behavioral control and self-efficacy to the TRA significantly improved the prediction of intentions and MVPA accounting for 28% and 5% of the variance, respectively. CONCLUSIONS: The results provided limited empirical support for the TPB among white adolescent girls; however, our findings suggest that the planned behavior framework has limited utility among African-American adolescent girls. The relatively weak link between intentions and MVPA observed in both population groups suggest that constructs external to the TPB may be more important mediators of physical activity behavior in adolescent girls.     

Confirmatory Factor Analysis and Sample Invariance of the Chinese Patient Satisfaction Questionnaire (ChPSQ-9) among Patients with Breast and Lung Cancer

Objectives:  Previous exploratory factor analysis of the 9-item Chinese Patient Satisfaction Questionnaire (ChPSQ-9) identified two dominant factors: doctor and nurse. The present study employed confirmatory factor analysis (CFA) to examine the factorial invariance of the ChPSQ-9 between and within samples of Chinese patients with breast or lung cancer.
Methods:  Longitudinal data were analyzed from Chinese breast and lung cancer patients who had completed the ChPSQ-9 during their first outpatient visit, at 3 months, and at 6 months after baseline. CFAs tested the fit of a one-factor model, a hierarchical model that comprised a general latent factor and two first-order factors, and a correlated model that comprised two correlated first-order factors to the data. The factorial invariance of the ChPSQ-9 between six independent samples across time was investigated using multigroup CFAs.
Results:  The CFA's results demonstrated a better fit of the correlated model over the one-factor model and the hierarchical model in the breast and lung cancer samples. The correlated model showed evidence of cross-sample and longitudinal factorial invariance. Patients were generally satisfied with services provided by doctors and nurses. Internal consistency of the scale was also good for both cancer samples across time.
Conclusions:  The ChPSQ-9 is a valid and reliable instrument to be employed among breast and lung cancer patients, in clinical settings or intervention research, to evaluate group differences in patient satisfaction and its association with intervention effectiveness.     

Predictors of stage transitions in the precaution adoption process model

PURPOSE: To explore psychosocial correlates and predictors of stage transitions in the precaution adoption process model (PAPM) for fruit intake. DesigN: A cohort completed three electronic questionnaires, at baseline (time 0), 35 days later (time 1), and another 32 days later (time 2). SETTING: Secured Internet Web site. SUBJECTS: A cohort of 735 adults was formed from a random sample of an existing Internet panel. The mean age was 37.5 years, 51% were women, and 90% were of Dutch origin. Most respondents (48%) had a medium level of education. MEASURES: Precaution adoption process model stage, risk perception, perception of own fruit intake level, attitude, pros, cons, subjective norms, social support, modeling, self-efficacy, and fruit intake (assessed using a food frequency questionnaire). ANALYSIS: Cross-sectional differences in psychosocial variables and fruit intake across PAPM stages at baseline were analyzed using analysis of variance with Tukey multiple comparisons tests. Predictors of PAPM stage transitions between time 0 and time 1 and between time 1 and time 2 were analyzed using logistic regression analysis. RESULTS: Factors related to attitude and social influences may be important if one is to decide to act, whereas strong self-efficacy may also be required for acting on the decision to act. CONCLUSION: Although the results should be replicated in a larger and more representative sample, the PAPM seems a good framework for studying fruit intake.     

Goals and intentions mediate efficacy beliefs and declining physical activity in high school girls

BACKGROUND: According to theory, girls who set goals about increasing their physical activity and who are dissatisfied with their current activity level are likely to form intentions to be active and to carry out those intentions, especially if they have high efficacy and control beliefs about being physically active. We tested those ideas while observing naturally occurring change during high school. METHODS: A cohort of 431 black and white girls was tested at the end of their 9th- and 12th-grade academic years. Confirmatory factor analysis established the structural invariance of the measures across the 3-year study period. Structural equation modeling and panel analysis were used to determine whether changes in goal setting and satisfaction would mediate relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. Testing occurred between February and May in 1999 and 2004. Data were analyzed in 2006. RESULTS: Goal setting and intention mediated the indirect relation between self-efficacy and change in physical activity. Perceived behavioral control and physical activity change were related directly and also indirectly by a path mediated through satisfaction and intention. Black girls had lower self-efficacy, but changes in other variables were unrelated to race. CONCLUSIONS: These observations of longitudinal relations elaborate application of self-efficacy theory and the theory of planned behavior to physical activity by showing that goal setting and satisfaction mediate the relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. The results encourage additional research to identify the sources and development of physical activity goals, and their attainment, among girls, and whether experimental manipulation of goals and intentions can mitigate the decline in girls' physical activity during high school.     

Television, physical activity, diet, and body weight status: the ARIC cohort

Objective

This study investigated the construct validity of a computerised self-assessment tool to measure psychological, social and environmental influences of young peoples' physical activity. First, analyses of the measure's factorial validity, invariance across, age, gender culture were conducted. Second, the ability of the derived subscales to discriminate between children representing different levels of self-reported and objectively measured physical activity behaviour was examined.

Methods

Participants were 1875 boys and 2078 girls (total = 3958) aged 9–10 years (n = 1955, mean age = 9.65 ± 0.42) and 15–16 years (n = 2003, mean age = 15.49 ± 0.50) from four European countries in Northern, Southern and Eastern Europe who took part in the European Youth Heart Study (EYHS). Children completed the computerised self-assessment tool with support from the researcher if requested. Self-reported exercise and an objective measure of physical activity (Actigraph model 7164) were used for additional construct validation purposes.

Results

Overall evidence of good fit indicating satisfactory factorial validity and cross-cultural, age and gender invariance for 3 of the 4 measurement models were obtained. The majority of measures were also significantly different for those with high versus low levels of physical activity.

Conclusion

Overall, the computerised questionnaire holds promise for use cross-culturally with male and female children and adolescents to measure perceived personal, social and environmental influences on physical activity. Further development of the measures pertaining to perceived environmental influences seems warranted.     

Predicting physical activity among adults with visual impairments using the theory of planned behavior

BackgroundUsing the theory of planned behavior (TPB), Haegele et al.¹ created the beliefs of individuals with visual impairments about physical activity scale (BIVIPA-1) to examine individuals with visual impairments’ (VI) motivation toward physical activity (PA). The overall factorial tenability of the BIVIPA-1 remains unclear due to its item configuration.Objective/hypothesisThe purposes of this cross-sectional study were to: (a) use confirmatory factor analysis to explore the structure of the expanded BIVIPA-2 and (b) test the predictive utility of TPB constructs on PA among adults with VI.MethodsAdults with VI (n = 236) completed the BIVIPA-2 and a multi-item PA recall instrument. A CFA was performed on the BIVIPA-2, and structural equation modeling was used to explore the relationship between theory constructs and PA.ResultsThe CFA results showed that the underlying structure of BIVIPA-2 was tenable for adults with VI based on TPB. Structural equation modeling showed limited support for the theorized predictive roles of theory variables on PA, as attitude predicted physical activity intention. Interestingly, subjective norm was a direct predictor for PA among adults with VI (β = 0.145).ConclusionsTPB had limited predictive utility for physical activity among individuals with VI. The predictive relationship of subjective norms on PA may be somewhat unique to this population. Researchers may consider expanding the model to examine social support and subjective norms constructs and PA among individuals with VI.     

Self-management strategies mediate self-efficacy and physical activity

BACKGROUND: Self-efficacy theory proposes that girls who have confidence in their capability to be physically active will perceive fewer barriers to physical activity or be less influenced by them, be more likely to pursue perceived benefits of being physically active, and be more likely to enjoy physical activity. Self-efficacy is theorized also to influence physical activity through self-management strategies (e.g., thoughts, goals, plans, and acts) that support physical activity, but this idea has not been empirically tested. METHODS: Confirmatory factor analysis was used to test the factorial validity of a measure of self-management strategies for physical activity. Next, the construct validity of the measure was tested by examining whether self-management strategies mediated the relationship between self-efficacy and self-reported physical activity, independently of several social-cognitive variables (i.e., perceived barriers, outcome expectancy value, and enjoyment), among cross-sectional samples of 6th grade (n=309) and 8th grade (n=296) girls tested between February 14 and March 17, 2002. Data were analyzed in 2004. RESULTS: Consistent with theory, self-efficacy had direct effects on the social-cognitive variables. The primary novel finding is that self-management strategies mediated the association of self-efficacy with physical activity in both samples. CONCLUSIONS: The measure of self-management strategies for physical activity yields valid scores among adolescent girls and warrants experimental study as a mediator of the influence of efficacy beliefs on physical activity.     

Individual motivation and social influence: a study of telemedicine adoption in China based on social cognitive theory

Objectives In recent years, telemedicine has emerged in China to help address problems concerning access to and the cost of medical treatment. The aim of this study was to explore the factors influencing residents’ adoption of telemedicine services. Methods Using social cognitive theory, we analyzed individual and environmental factors that influence patients’ behavioral intentions with respect to telemedicine. We distributed questionnaires to patients who had used telemedicine in Dongtai, and 279 valid samples were collected. Results The reliability and validity were acceptable. Eight of the 9 hypotheses were supported at the 0.05 significance level. Motivation had positive correlations with self-efficacy and trust, self-rated health was positively correlated with trust, subjective norms were positively correlated with self-efficacy and trust, institution size was positively correlated with trust, and self-efficacy and trust were positively correlated with patients’ intentions to use telemedicine. Conclusions Motivation and subjective norms can promote behavioral intentions by promoting self-efficacy and trust, and self-rated health and institution size can promote behavioral intentions by promoting trust. These findings explain the antecedents of patients’ behavioral intentions to use telemedicine and support specific policy recommendations for the development of telemedicine services.     

Measuring enjoyment of physical activity in adolescent girls.

BACKGROUND: Enjoyment has been implicated as a determinant of physical activity among youth, but advances in understanding its importance have been limited by the use of measures that were not adequately validated. The present study examined: (1) the factorial validity of the Physical Activity Enjoyment Scale (PACES), and (2) the construct validity of PACES scores. METHODS: Adolescent girls (N=1797), who were randomly assigned to calibration (n=899) and cross-validation (n=898) samples, completed the PACES and measures of factors influencing enjoyment of physical education, physical activity, and sport involvement. The factorial validity of the PACES and the measure of factors influencing enjoyment of physical education was tested using exploratory and confirmatory factor analysis. The hypothesized relationships among the measures were tested using structural equation modeling. RESULTS: Unidimensional models fit the PACES and the measure of factors influencing enjoyment of physical education in the calibration and cross-validation samples. The hypothesized relationships between the PACES and the measures of factors influencing enjoyment of physical education, physical activity, and sport involvement were supported in the entire sample, were similar in African-American and Caucasian girls, and were independent of physical fitness. CONCLUSIONS: Evidence of factorial validity and convergent evidence for construct validity indicate that the PACES is a valid measure of physical activity enjoyment among adolescent girls, suitable for use as a mediator variable in interventions designed to increase physical activity.     

Factorial invariance found in survey instrument measuring arthritis-related health beliefs among African-Americans and Whites

OBJECTIVE: Reliable and valid instruments for measuring health beliefs related to arthritis and total joint arthroplasty (TJA) are lacking. The present study examined the factorial invariance of an Arthritis-related Health Belief Instrument (AHBI) that measures four constructs: severity of arthritis, susceptibility of arthritis to get worse, and perceived benefits and barriers of TJA. STUDY DESIGN AND SETTING: In an urban primary care clinic setting, African-American (AA) and White (W) patients (n=664) with at least a moderately severe degree of osteoarthritis completed the AHBI. For the cross-sectional data on the first 120 enrolled participants, exploratory factor analysis was performed to derive the initial factor structures. For the remaining 544 participants, single-group and multi-group confirmatory factor analyses (CFA) were performed to assess factorial invariance. RESULTS: The CFA analyses revealed that a four-factor model was invariant across race. CONCLUSION: The findings of invariance across race support the use of the AHBI to measure ethnic group differences in health beliefs as they relate to arthritis and TJA. Future analyses should continue to assess other aspects of reliability and validity of the AHBI.     

Sociocognitive Predictors of Condom Use and Intentions Among Adolescents in Three Sub-Saharan Sites

Many HIV intervention programs in sub-Saharan Africa have applied social cognitive theories such as the theory of planned behavior. However, a recent sub-Saharan African review was unable to show increased effectiveness for theory-based interventions. This study assessed whether the predictive value of attitudes, subjective norms, self-efficacy, and intention was similar to studies in Europe and the U.S., and whether there were differences between three sub-Saharan sites. Longitudinal multigroup structural equation modeling was used to assess whether attitudes, subjective norms, and self-efficacy predicted condom use intentions and condom use (after 6 months) among adolescents in three sites, namely Cape Town (South Africa; N = 625), Dar es Salaam (Tanzania; N = 271), and Mankweng (South Africa; N = 404). Condom use intentions were predicted by subjective norms and self-efficacy in all three sites. Attitudes were not related to intentions in Dar es Salaam and were moderately related to intentions in Cape Town and Mankweng. The proportions of explained variance in intentions and behavior were decent (37–52 and 9–19 %, respectively). Although significant differences in predictive value were found between sites and in comparison to European and U.S. studies, intentions could adequately be explained by attitudes, subjective norms, and self-efficacy. However, the limited proportions of variance in behavior explained by intentions could signify the importance of contextual and environmental factors. Future studies are recommended to use an integrative approach that takes into account both individual and contextual factors, as well as social and environmental differences.     

Validity of scales measuring the psychosocial determinants of HIV/STD-related risk behavior in adolescents.

We examined the content, construct and concurrent validity of scales to assess beliefs and self-efficacy related to adolescents' sexual risk behavior. We addressed content validity in the scale development process by drawing on literature and theory, and by pre-testing items with focus groups. We used confirmatory factor analysis of two models, an intercourse involvement model and a condom use model, to assess construct validity. The final intercourse involvement model included three scales: norms about sexual intercourse, attitudes about sexual intercourse and self-efficacy in refusing sex. The final condom use model included five scales: norms about condoms, attitudes about condom use, self-efficacy in communicating about condoms, self-efficacy in buying/using condoms and barriers to condom use. After two alterations to the models, the chi 2 and other indices indicated that the data fit the models well. Supporting the concurrent validity of the scales, high school students who had never had sexual intercourse had more negative attitudes toward sexual intercourse among teenagers, perceived norms toward sexual intercourse among teenagers to be more negative and expressed greater self-efficacy in refusing sex than did those who had experienced sexual intercourse. Consistent condom users had more positive attitudes and norms about condoms, had higher self-efficacy in communicating about and buying/using condoms, and perceived fewer barriers to condom purchase and use than did inconsistent condom users.     

Weight-bearing physical activity among girls and mothers: relationships to girls' weight status

OBJECTIVE: To assess weight-bearing physical activity (WBPA) barriers, benefits, self-efficacy, social influence, and behaviors [WBPA and physical activity (PA)] among girls and their mothers according to girls' weight status (nonoverweight vs. overweight). RESEARCH METHODS AND PROCEDURES: Participants were 9- to 11-year-old girls (n = 295) and their mothers who participated in the baseline assessment of a nutrition and PA intervention trial. Girls' and mothers' WBPA attitudes and mothers' WBPA behaviors were self-reported on questionnaires. Girls' WBPA and total PA behaviors were self-reported using a structured interview (Physical Activity Checklist Interview). Stature and weight were measured by standardized anthropometrics. Overweight status was based on BMI. RESULTS: Compared with nonoverweight girls, overweight girls were significantly more likely to report barriers to WBPA participation and perceive social influence from family and friends to do more WBPA. They were also significantly less likely to report self-efficacy regarding WBPA and to believe that they did enough WBPA. Compared with mothers of nonoverweight girls, mothers of overweight girls were significantly more likely to report that it is difficult to persuade their daughters to do more WBPA and significantly less likely to report that WBPA was fun for their daughters. Girls' overweight status was not associated with girls' reports of minutes spent per week in PA or WBPA. DISCUSSION: The present study's findings of lower WBPA self-efficacy, lack of enjoyment of WBPA, and higher perceived social influence to do WBPA among overweight girls suggest that efforts are needed to promote physical competencies and positive perceptions of PA among overweight girls.     

Predicting fruit consumption: cognitions, intention, and habits

OBJECTIVE: To study predictors of fruit intake in a sample of 627 adults. DESIGN: Potential predictors of fruit intake were assessed at baseline, and fruit intake was assessed at two-week follow-up with self-administered questionnaires distributed by e-mail. SETTING: The study was conducted among Dutch adult members of an Internet research panel. PARTICIPANTS: A random sample of 627 adults aged 18-78. VARIABLES MEASURED: Attitudes, subjective norms, self-efficacy, expected pros and cons, habit strength, intention, and fruit intake. Fruit intake was assessed with a validated food-frequency questionnaire. ANALYSIS: Hierarchical linear and logistic regression analyses. Alpha < .05 was considered statistically significant. RESULTS: Sex, attitudes, subjective norms, perceived pros, different self-efficacy expectations, and habit strength were significantly associated with the intention to eat two or more servings of fruit per day. Age, intentions, and habit strength were significant predictors of consumption of two or more servings of fruit per day. CONCLUSIONS AND IMPLICATIONS: The results confirm that Theory of Planned Behavior constructs predict fruit intake, and that habit strength and different self-efficacy expectations may be additional determinants relevant to fruit intake. Because habitual behavior is considered to be triggered by environmental cues, fruit promotion interventions should further explore environmental change strategies.     

Psychometric properties of the Center for Epidemiologic Studies Depression Scale (CES-D) in French clinical and nonclinical adults

BackgroundPrevious research on the Center for Epidemiologic Studies Depression Scale (CES-D) has five main limitations. First, no study provided evidence of the factorial equivalence of this instrument across samples of depressive and community participants. Second, only one study included systematic tests of measurement invariance based on confirmatory factor analyses (CFA), and this study did not consider the higher-order factor structure of depression, although it is the CES-D global scale score that is most often used in the context of epidemiological studies. Third, few studies investigated the screening properties of the CES-D in non-English-language samples and their results were inconsistent. Fourth, although the French version of the CES-D has been used in several previous studies, it has never been systematically validated among community and/or depressed adults. Finally, very few studies have taken into account the ordered-categorical nature of the CES-D answer scale. The purpose of the study reported herein was therefore to examine the construct validity (i.e., factorial, reliability, measurement invariance, latent mean invariance, convergence, and screening properties) of the CES-D in a French sample of depressed patients and community adults.MethodsA total sample of 469 participants, comprising 163 clinically depressed patients and 306 community adults, was involved in this study. The factorial validity, and the measurement and latent mean invariance of the CES-D across gender and clinical status, were verified through CFAs based on ordered-categorical items. Correlation and receiver operator characteristic curves were also used to test the convergent validity and screening properties of the CES-D.ResultsThe present results: (i) provided support for the factor validity and reliability of a second-order measurement model of depression based on responses to the CES-D items; (ii) revealed the full measurement invariance of the first- and second-order measurement models across gender; (iii) showed the partial strict measurement invariance (four uniquenesses had to be freely estimated, but the factor variance–covariance matrix also proved fully invariant) of the first-order factor model and the complete measurement invariance of the second-order model across patients and community adults; (iv) revealed a lack of latent mean invariance across gender and across clinical and community subsamples (with women and patients reporting higher scores on all subscales and on the full scale); (v) confirmed the convergent validity of the CES-D with measures of depression, self-esteem, anxiety, and hopelessness; and (vi) demonstrated the efficacy of the screening properties of this instrument among clinical and nonclinical adults.ConclusionThis instrument may be useful for assessing depressive symptoms or for the screening of depressive disorders in the context of epidemiological studies targeting French patients and community men and women with a background similar to those from the present study.     

Factor structure for the frailty syndrome was consistent across Europe

ObjectivesWe explored the measurement properties of frailty with the goal of optimizing frailty assessment according to phenotype definition of Fried and comparing measurement properties across countries.Study Design and SettingData are from the Survey of Health, Ageing and Retirement in Europe (n = 27,938), a population-based study of community-dwelling adults aged ≥50 years. Frailty was specified as a unidimensional construct, and measurement invariance across the 12 countries was tested. To assess our measurement model, we used confirmatory factor analysis (CFA) and multigroup CFA to assess measurement invariance.ResultsThe unidimensional model fit the data well (adjusted χ²(48) = 82.74, P = 0.001), and the same structure was satisfactory for all countries. Inclusion of equality constraints led to significant model deterioration (adjusted χ²diff(88) = 995.05, P < 0.001), suggesting differences in parameters across countries. Spain was removed from further analyses, and equality constraints for Greece, Sweden, Israel, Italy, and France were not tenable. Accounting for these led to satisfactory model fit (adjusted χ²(113) = 414.33, P < 0.001). Significant mean frailty differences were identified.ConclusionThe relationships between the construct of frailty and indicators, although broadly constant, do vary across some countries. Furthermore, there was evidence of differing levels of frailty for the middle-aged and older populations across European countries.     

Psychological predictors of physical activity in the diabetes prevention program

OBJECTIVE: To identify the baseline psychological variables before receiving a Diabetes Prevention Program (DPP) lifestyle intervention that predict physical activity levels (PALs) at baseline, 1 year, and end of study (2 to 3 years after randomization). DESIGN AND SUBJECTS: Of the final 293 DPP lifestyle participants randomized, 274 (94%) completed validated questionnaires at baseline assessing stage of change for PAL, exercise self-efficacy, perceived stress, depression, and anxiety. STATISTICAL ANALYSES PERFORMED: Correlations and stepwise multiple regression analyses. RESULTS: At baseline, this subset was similar to the entire DPP lifestyle cohort: mean age was 52.5 years, 65% were women, and mean PAL was 15.7 metabolic equivalent hours per week. Higher levels of baseline leisure PAL correlated with greater readiness to change PAL (r=0.44, P<0.0001), higher exercise self-efficacy (r=0.18, P=0.002), and lower levels of perceived stress (r=-0.16, P=0.009), depression (r=-0.18, P=0.003), and anxiety (r=-0.14, P=0.03), with similar correlations at 1 year and end of study. In multivariate models, being a man, lower levels of depression, and lower body mass index were independent correlates of higher baseline leisure PAL; being a man, greater baseline exercise self-efficacy, and activity level were independent correlates of greater leisure PAL levels at 1 year and end of study. Greater readiness to change PAL at baseline was also an independent correlate of greater PAL at end of study. CONCLUSIONS: In this representative sample of DPP lifestyle participants, being a man, lower body mass index, greater readiness for change in PAL, higher exercise self-efficacy, and lower perceived stress, depression, and anxiety scores correlated with higher levels of baseline PAL with similar patterns at 1 year and end of study. These findings may help determine which patients are most likely to increase PAL in lifestyle intervention programs.