Construction of sum indices for impairment and A&P restrictions
| Construct | Variable | Measurement | Coding for ‘yes’ | PCA* | CFA† |
|---|---|---|---|---|---|
| Impairment | Symptoms load | Two or more symptoms | 1 | 0.16 | 1 |
| Problems with biting | Unable to bite on hard food | 1 | 0.12 | 0.15 | |
| Problems with seeing | Seeing is fair or worse (either distance or reading) | 1 | 0.14 | 0.22 | |
| Problems with hearing | Hearing is fair or worse | 1 | 0.10 | 0.21 | |
| Mobility | One or more mobility, arm function and fine motor limitations | 1 | 0.18 | 0.9 | |
| Orientation to date, month, year and day of week | Less than good | 1 | 0.15 | 0.07 | |
| Mathematical performance | Score 1 or 2 (range 1–5) | 1 | 0.18 | 0.15 | |
| Grip strength | Male: <37/female: <21 | 1 | 0.15 | 0.19 | |
| Depressive symptoms | Eurodcat | 1 | 0.16 | 0.53 | |
| Verbal fluency score | Less than 15 | 1 | 0.23 | 0.11 | |
| Ten words list | Three or less | 1 | 0.24 | 0.12 | |
| Delay ten words list | Two or less | 1 | 0.25 | 0.15 | |
| Range sum index | |||||
| A&P restrictions | Reported problems with… | Dressing, including putting on shoes and socks | 1 | 0.24 | 1 |
| Walking across a room | 1 | 0.34 | 0.19 | ||
| Bathing or showering | 1 | 0.29 | 0.40 | ||
| Eating, such as cutting up your food | 1 | 0.29 | 0.07 | ||
| Getting in and out of bed | 1 | 0.27 | 0.54 | ||
| Using the toilet, including getting up or down | 1 | 0.30 | 0.22 | ||
| Preparing a hot meal | 1 | 0.22 | 0.19 | ||
| Shopping for groceries | 1 | 0.26 | 0.63 | ||
| Making telephone calls | 1 | 0.19 | 0.06 | ||
| Taking medications | 1 | 0.26 | 0.11 | ||
| Doing work around the house or garden | 1 | 0.24 | 1.14 | ||
| Managing money, such as paying bills and keeping track of expenses | 1 | 0.27 | 0.09 | ||
| Range sum index | 0–12 | ||||
*Principal component analysis (PCA) with 8615 cases from the selected countries for 2004; numbers are loadings on respective components, two components impairment and A&P restriction with eigenvalues >2 extracted.
†Confirmatory factor analysis (CFA) for the final sample (n=4864). Numbers indicate loadings on component impairment and A&P restriction; the first items were used as scalars.