The study, led by Márta Fekete of Uzsoki Hospital in Budapest together with Patricia Lajko of Semmelweis University and colleagues including corresponding author Xenia Gonda, recruited 223 Hungarian-speaking participants aged 50 and above. Each respondent completed a Hungarian adaptation of the CASP-19 that used a modified agreement-based response format — a seemingly small design decision that, as the authors show, can ripple through the entire measurement. The work was approved by the Scientific and Research Ethics Committee of the Medical Research Council of Hungary, and the team supplemented the CASP-19 with a battery of established quality-of-life instruments to test whether the scale actually measures what it claims to measure.

The headline number is impressive. The full 19-item questionnaire achieved a Cronbach’s alpha of 0.91, a statistic that ranges from zero to one and expresses how tightly the items hang together; anything above 0.90 is generally considered excellent for a multi-dimensional scale. In plain terms, when a Hungarian respondent reports a strong sense of control over their life, they are very likely to also report high autonomy, self-realization and pleasure. For researchers and clinicians who want a single summary score of psychosocial quality of life in later life, the Hungarian CASP-19 delivers one they can trust.

But the deeper story lies in the factor analysis — the statistical machinery used to ask how many separate psychological dimensions actually live inside a questionnaire. The team ran a principal axis factoring with varimax rotation, a classical exploratory technique that extracts underlying factors from the correlations among items. This yielded a four-factor solution explaining 53.1 percent of the total variance, superficially matching the theory. Yet when the researchers applied sensitivity analyses — parallel analysis, which compares observed factors against those arising from random noise, and oblique rotation, which allows factors to correlate — the evidence favoured fewer factors. The tidy four-part architecture of the CASP framework, it turns out, is partly in the eye of the beholder.

The most telling detail concerns the boundary between Control and Autonomy, two dimensions that sound distinct in theory but blur in practice. In the Hungarian data, all of the Autonomy items and most of the Control items loaded onto a single common factor, meaning that respondents do not experience these two ideas as psychologically separable. Control, in the CASP framework, refers to the sense of being able to influence one’s own life, while Autonomy concerns freedom from the dictates of others. In the lived experience of Hungarian adults over 50, however, having free choice and having influence apparently merge into one broader feeling of personal agency. Consistent with this, the Autonomy subscale showed the weakest internal consistency of the four, with an alpha of just 0.69 — below the conventional 0.70 threshold that psychometricians typically demand.

To confirm these exploratory findings, the researchers turned to confirmatory factor analysis, the stricter sibling of exploratory methods. Rather than letting the data suggest a structure, CFA tests pre-specified structural models and grades how well each fits. Crucially, the team estimated their models from polychoric correlations using the weighted least squares mean- and variance-adjusted estimator, known as WLSMV — a technical choice that matters enormously here. The CASP-19 uses ordered response categories rather than continuous measurements, and treating such ordinal data with methods designed for continuous variables can distort factor structures. Polychoric correlations and WLSMV respect the ordinal nature of the responses, making this one of the more methodologically careful adaptations of the scale to date.

Validity was assessed from two directions. On the convergent side, the CASP-19 correlated moderately to strongly with three independent measures: the EuroQol 5-Dimension 5-Level questionnaire, the 36-Item Short Form Health Survey, and the Mental Health Quality of Life questionnaire. This pattern is exactly what one hopes to see — the scale tracks other quality-of-life and well-being instruments closely enough to be measuring something real, but not so perfectly that it is redundant with them. The correlations thus anchor the Hungarian CASP-19 within the wider family of health and well-being measures, giving researchers confidence that scores can be compared and integrated across studies.

The study also tackled a practical question that increasingly confronts ageing research: does it matter whether older adults fill in a paper questionnaire or an online version? The authors compared total CASP-19 scores between respondents who completed the paper-based form and those who used the online version, matching participants on background characteristics using propensity scores and then running matched-pair t-tests. The matched subgroups showed no difference in total scores. But the researchers are admirably cautious about this finding: the matched sample consisted of different individuals rather than the same people completing both formats, and it contained only 26 pairs. As they emphasize, this cannot be interpreted as evidence of true measurement equivalence between the two administration modes — a caveat that should temper any rush to digital data collection in later-life surveys.

Why does all this matter beyond Hungary? Populations across Europe and much of the world are ageing rapidly, and instruments like the CASP-19 feed directly into policy decisions about pensions, health services and social care. If a scale’s subscale scores are used to target interventions — say, programmes designed to boost autonomy specifically — but the data show that autonomy and control are empirically inseparable in a given culture, then the theoretical scaffolding behind those programmes wobbles. The Hungarian findings add a cross-cultural data point to a growing international conversation about whether the CASP framework’s four dimensions are universal psychological realities or, at least in part, artefacts of the original British context in which the scale was developed.

The authors’ conclusions are measured. They report that the Hungarian CASP-19 demonstrated high internal consistency and interpretable structural characteristics, supporting its use for assessing psychosocial quality of life in adults aged 50 and over. At the same time, they state plainly that their findings did not support a strictly separated four-dimensional interpretation, particularly with regard to the Control and Autonomy domains. The study also highlights the methodological relevance of response format adaptation — a reminder that how a question is asked, not just what it asks, shapes what researchers discover about the quality of later life. For anyone measuring well-being in ageing populations, the message is clear: trust the total score, but handle the subscales with care.

Subject of Research: Psychometric evaluation of the Hungarian CASP-19 quality-of-life scale in adults aged 50 and over

Article Title: Psychometric evaluation and factor structure of the Hungarian CASP-19: methodological and practical implications from an ageing population

Article References: Fekete, M., Lajko, P., Szekeres, T., Rethy, L. J., & Gonda, X. (2026). Psychometric evaluation and factor structure of the Hungarian CASP-19: methodological and practical implications from an ageing population. BMC Psychology. https://doi.org/10.1186/s40359-026-05810-w

Image Credits: AI Generated

DOI: 10.1186/s40359-026-05810-w

Keywords: CASP-19, quality of life, psychometrics, factor analysis, ageing, older adults, Hungary, internal consistency, confirmatory factor analysis, cross-cultural adaptation, response format, psychosocial well-being