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The attitudes to ageing questionnaire: Mokken scaling analysis.

Shenkin SD, Watson R, Laidlaw K, Starr JM, Deary IJ - PLoS ONE (2014)

Bottom Line: These results were compared with factor analysis using exploratory structural equation modelling.The previously-described factor structure is mostly confirmed.This shows what older people themselves consider important regarding their own ageing.

View Article: PubMed Central - PubMed

Affiliation: Department of Geriatric Medicine, University of Edinburgh, Edinburgh, Scotland, United Kingdom; Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh, Scotland, United Kingdom.

ABSTRACT

Background: Hierarchical scales are useful in understanding the structure of underlying latent traits in many questionnaires. The Attitudes to Ageing Questionnaire (AAQ) explored the attitudes to ageing of older people themselves, and originally described three distinct subscales: (1) Psychosocial Loss (2) Physical Change and (3) Psychological Growth. This study aimed to use Mokken analysis, a method of Item Response Theory, to test for hierarchies within the AAQ and to explore how these relate to underlying latent traits.

Methods: Participants in a longitudinal cohort study, the Lothian Birth Cohort 1936, completed a cross-sectional postal survey. Data from 802 participants were analysed using Mokken Scaling analysis. These results were compared with factor analysis using exploratory structural equation modelling.

Results: Participants were 51.6% male, mean age 74.0 years (SD 0.28). Three scales were identified from 18 of the 24 items: two weak Mokken scales and one moderate Mokken scale. (1) 'Vitality' contained a combination of items from all three previously determined factors of the AAQ, with a hierarchy from physical to psychosocial; (2) 'Legacy' contained items exclusively from the Psychological Growth scale, with a hierarchy from individual contributions to passing things on; (3) 'Exclusion' contained items from the Psychosocial Loss scale, with a hierarchy from general to specific instances. All of the scales were reliable and statistically significant with 'Legacy' showing invariant item ordering. The scales correlate as expected with personality, anxiety and depression. Exploratory SEM mostly confirmed the original factor structure.

Conclusions: The concurrent use of factor analysis and Mokken scaling provides additional information about the AAQ. The previously-described factor structure is mostly confirmed. Mokken scaling identifies a new factor relating to vitality, and a hierarchy of responses within three separate scales, referring to vitality, legacy and exclusion. This shows what older people themselves consider important regarding their own ageing.

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Related in: MedlinePlus

Factor structure of the AAQ scale.Diagrammatic representation of structural equations representing hypothesised model of the relationship between variables in the AAQ. Squares represent the AAQ variables, ovals represent first-order latent variables. Standardised regression weights of first-order factors on second order stress factor are shown; standardised regression weights of SINS items on first-order factors are shown in Table 5; broken arrows represent error variance; intercorrelated error variances are shown in Table 5.
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pone-0099100-g001: Factor structure of the AAQ scale.Diagrammatic representation of structural equations representing hypothesised model of the relationship between variables in the AAQ. Squares represent the AAQ variables, ovals represent first-order latent variables. Standardised regression weights of first-order factors on second order stress factor are shown; standardised regression weights of SINS items on first-order factors are shown in Table 5; broken arrows represent error variance; intercorrelated error variances are shown in Table 5.

Mentions: Inspection of eigenvalues suggested a five-factor solution explaining 51% of the post-rotational variance, but the parallel analysis suggested a maximum of four factors explaining 46.5% of the post-rotational variance, and the scree slope method between three to four factors, the three factor solution explaining 41% of the post-rotational variance. Both a four- and a three-factor solution were inspected following oblique rotation; the four-factor solution produced one trivial factor with only two items loading and the distribution of items across factors was hard to interpret. However, the three factor solution (Table 3) produced a reasonably simple solution (one whereby loadings were high on putative factors with low loadings elsewhere). Some cross-loading was evident—often a reason to remove items and re-rotate—but the distribution of items, with two exceptions, showed remarkable congruence with the factor solution reported by Laidlaw et al, 2007. The two exceptions were the items ‘My identity is not defined by my age’, previously loading on the Physical Change factor and now loading on the Psychosocial Loss factor, and ‘I am losing my physical independence as I get older’, previously loading on the Psychosocial Loss factor and now loading on the Physical Change factor. The first order factor structure is shown in Figure 1 and the correlated residuals are shown in Table 4. The proposed solution and fit indices are shown in Tables 5 and 6, respectively. The GFI, AGFI and CFI all exceeded 0.90 and the RMSEA was lower than 0.06. With the reduction in degrees of freedom in the model, the value of Chi-square reduced, but the high, significant value of Chi-square—which should ideally be low and non-significant—in the final model is probably due to the large sample size.


The attitudes to ageing questionnaire: Mokken scaling analysis.

Shenkin SD, Watson R, Laidlaw K, Starr JM, Deary IJ - PLoS ONE (2014)

Factor structure of the AAQ scale.Diagrammatic representation of structural equations representing hypothesised model of the relationship between variables in the AAQ. Squares represent the AAQ variables, ovals represent first-order latent variables. Standardised regression weights of first-order factors on second order stress factor are shown; standardised regression weights of SINS items on first-order factors are shown in Table 5; broken arrows represent error variance; intercorrelated error variances are shown in Table 5.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4043998&req=5

pone-0099100-g001: Factor structure of the AAQ scale.Diagrammatic representation of structural equations representing hypothesised model of the relationship between variables in the AAQ. Squares represent the AAQ variables, ovals represent first-order latent variables. Standardised regression weights of first-order factors on second order stress factor are shown; standardised regression weights of SINS items on first-order factors are shown in Table 5; broken arrows represent error variance; intercorrelated error variances are shown in Table 5.
Mentions: Inspection of eigenvalues suggested a five-factor solution explaining 51% of the post-rotational variance, but the parallel analysis suggested a maximum of four factors explaining 46.5% of the post-rotational variance, and the scree slope method between three to four factors, the three factor solution explaining 41% of the post-rotational variance. Both a four- and a three-factor solution were inspected following oblique rotation; the four-factor solution produced one trivial factor with only two items loading and the distribution of items across factors was hard to interpret. However, the three factor solution (Table 3) produced a reasonably simple solution (one whereby loadings were high on putative factors with low loadings elsewhere). Some cross-loading was evident—often a reason to remove items and re-rotate—but the distribution of items, with two exceptions, showed remarkable congruence with the factor solution reported by Laidlaw et al, 2007. The two exceptions were the items ‘My identity is not defined by my age’, previously loading on the Physical Change factor and now loading on the Psychosocial Loss factor, and ‘I am losing my physical independence as I get older’, previously loading on the Psychosocial Loss factor and now loading on the Physical Change factor. The first order factor structure is shown in Figure 1 and the correlated residuals are shown in Table 4. The proposed solution and fit indices are shown in Tables 5 and 6, respectively. The GFI, AGFI and CFI all exceeded 0.90 and the RMSEA was lower than 0.06. With the reduction in degrees of freedom in the model, the value of Chi-square reduced, but the high, significant value of Chi-square—which should ideally be low and non-significant—in the final model is probably due to the large sample size.

Bottom Line: These results were compared with factor analysis using exploratory structural equation modelling.The previously-described factor structure is mostly confirmed.This shows what older people themselves consider important regarding their own ageing.

View Article: PubMed Central - PubMed

Affiliation: Department of Geriatric Medicine, University of Edinburgh, Edinburgh, Scotland, United Kingdom; Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh, Scotland, United Kingdom.

ABSTRACT

Background: Hierarchical scales are useful in understanding the structure of underlying latent traits in many questionnaires. The Attitudes to Ageing Questionnaire (AAQ) explored the attitudes to ageing of older people themselves, and originally described three distinct subscales: (1) Psychosocial Loss (2) Physical Change and (3) Psychological Growth. This study aimed to use Mokken analysis, a method of Item Response Theory, to test for hierarchies within the AAQ and to explore how these relate to underlying latent traits.

Methods: Participants in a longitudinal cohort study, the Lothian Birth Cohort 1936, completed a cross-sectional postal survey. Data from 802 participants were analysed using Mokken Scaling analysis. These results were compared with factor analysis using exploratory structural equation modelling.

Results: Participants were 51.6% male, mean age 74.0 years (SD 0.28). Three scales were identified from 18 of the 24 items: two weak Mokken scales and one moderate Mokken scale. (1) 'Vitality' contained a combination of items from all three previously determined factors of the AAQ, with a hierarchy from physical to psychosocial; (2) 'Legacy' contained items exclusively from the Psychological Growth scale, with a hierarchy from individual contributions to passing things on; (3) 'Exclusion' contained items from the Psychosocial Loss scale, with a hierarchy from general to specific instances. All of the scales were reliable and statistically significant with 'Legacy' showing invariant item ordering. The scales correlate as expected with personality, anxiety and depression. Exploratory SEM mostly confirmed the original factor structure.

Conclusions: The concurrent use of factor analysis and Mokken scaling provides additional information about the AAQ. The previously-described factor structure is mostly confirmed. Mokken scaling identifies a new factor relating to vitality, and a hierarchy of responses within three separate scales, referring to vitality, legacy and exclusion. This shows what older people themselves consider important regarding their own ageing.

Show MeSH
Related in: MedlinePlus