Translation and cultural validation of P-PASS; Content validity
During the translation and cultural validation of P-PASS, the expert panel decided that one CIADL task (bingo) should be removed because it was not relevant for independent living of the older adult Portuguese population. ‘Bill paying by check’, ‘checkbook balancing’, ‘mailing bills’, ‘obtaining critical information from auditory media’, ‘obtaining critical information from visual media’, ‘flashlight repair’, and ‘oven use’ were combined or adapted to yield ‘bill paying by ATM’, ‘obtaining critical information from the TV’, ‘changing TV command batteries’, and ‘microwave use’. Thus, the P-PASS consists of 22 task items: five FM, three BADL, ten CIADL, and four PIADL. Table 3 shows the 22 tasks included in the P-PASS. The independence, safety, and adequacy scoring system from the original pass was retained. When administered to a group of older adults and disabled adults no major concerns were raised about the content of the P-PASS.
Reliability
As in the original PASS structure, Cronbach’s alpha indicators evidenced an almost perfect internal consistency for FM (independence: 0.927; safety: 0.916; adequacy: 0.917), PIADL (independence: 0.924; safety: 0.911; adequacy: 0.904), and CIADL (independence: 0.951; adequacy: 0.939), and a substantial agreement for BADL (independence: 0.787; safety: 0.755; adequacy: 0.782).
Moreover, Cohen’s kappa, measuring the agreement between professionals when assessing the same subject, and performed in a sample of 30 individuals (13 of them females) recruited from the Association of Cerebral Palsy of Coimbra, provided almost perfect scores (independence: from 0.917 to 1.000; safety: from 0.920 to 1.000; adequacy: from 0.819 to 1.000). The only exception was the moderate agreement (0.591) on the adequacy parameter of the ‘bed mobility’ task, where six out of 30 pairs of professionals did not agree, changing scores 2 and 3.
Construct validity
A sample composed of 98 clients was recruited from: a Medium Duration Continuing Care Unit (37), a Night Center of a Rest Home (15), the Association of Cerebral Palsy of Coimbra (30), and the community (16). Subjects had a mean age of 64.2 ± 22.9 years (median: 68.5 years), 38.8% were over 80 years old, and 61.2% were female. In 38% of the cases, the P-PASS was applied in the context of a Continued Care Unit. Table 4 presents the results after administering the P-PASS to our sample.
Among the FM tasks, ‘stair use’ had the lowest scores (independence: 1.71; safety: 1.62; adequacy: 1.50), whereas ‘indoor walking’ had the highest scores (independence: 2.54; safety: 2.47; adequacy: 2.21). ‘Trimming toenails’ was the most difficult BADL task to perform (independence: 1.13; safety: 1.00; adequacy: 0.71) and ‘oral hygiene’ was the least problematic BADL task (independence: 2.53; safety: 2.56; adequacy: 2.32). For the PIADL tasks, the scores were more similar to each other. However, ‘changing bed linens’ scores were the lowest (independence: 1.55; safety: 1.65; adequacy: 1.35) and ‘taking out garbage’ the highest (independence: 2.14; safety: 1.98; adequacy: 1.79). Lastly, for CIADL tasks, the lowest scored tasks were ‘bill paying by ATM’ (independence: 1.61; adequacy: 1.60) and ‘stovetop use’ (independence: 1.64; safety: 1.37; adequacy: 1.51); the highest were the ‘use of sharp utensils’ (independence: 2.37; safety: 2.41; adequacy: 2.13) and ‘telephone use’ (independence: 2.18; adequacy: 1.87). ‘Obtaining critical information from TV’ also yielded high scores (independence: 2.12; adequacy: 2.01). Following the original PASS scoring system, six tasks were not scored for safety because they did not present immediate danger to the individual or the environment: ‘shopping’, ‘bill paying by ATM’, ‘telephone use’, ‘obtaining critical information from the TV’, ‘changing TV command batteries’, and ‘home safety’.
Testing construct validity, in relation to age (Table 5), in general, the majority of scores were significantly lower for individuals 80 years old or older than for younger individuals. However, no differences were found for the FM task ‘stair use’ (independence: p=0.358; safety: p=0.298; adequacy p=0.628), for BADL and independence tasks ‘oral hygiene’ (p=0.263) and ‘trimming toenails’ (p=0.191), and for CIADL tasks ‘stovetop use’ (independence: p=0.247; adequacy: p=0.268) and ‘use of sharp utensils’ (independence: p=0.281; safety: p=0.808).
When analyzing the impact of gender (Table 6) on the performance of the 22 tasks for independence, safety and adequacy, in general, no significant differences were found between men and women. There were, however, two exceptions for independence, with men scoring higher than women: ‘bill paying by ATM’ (p=0.035) and ‘changing TV command batteries’ (p=0.052).
For structural validity, applying principal components factor analysis, we obtained very good scores for KMO (independence: 0.944; safety: 0.924; adequacy: 0.928) and for significance associated to Bartlett's test of sphericity (independence: <0.001; safety: <0.001; adequacy: <0.001). In general, all dimensions followed the criteria for a good factor structure. However, the BADL task ‘trimming toenails’, independent of the number of factors selected, always appeared alone in a sole factor. Therefore, we decided to drop it from this analysis.
Looking at the independence parameter, we found three factors that explained 80.8% of the total variance. FM and BADL tasks were together in one factor and CIADL and PIADL tasks were each one factor. However, contrary to the original structure, ‘stovetop use’ belonged to the PIADL factor and the tasks ‘use of sharp utensils’, ‘microwave use’ and ‘taking out garbage’ belonged to the first factor together with FM and BADL tasks.
Concerning safety, an almost similar situation to independence was found. That is, three factors explained 77.1% of the total variance. The first factor was formed by FM and BADL tasks, the second one by PIADL tasks and the third one by CIADL tasks. However, ‘medication use’ was considered as belonging to the first factor, the tasks ‘stair use’ and ‘use of sharp utensils’ as belonging to the PIADL factor, and, lastly, the tasks ‘stovetop use’ and ‘microwave use’ as belonging to CIADL factor.
Finally, considering the adequacy parameter, we also found three factors explaining 77.1% of the total variance. The first factor also included FM and BADL tasks, the second factor encompassed PIADL tasks, and the third, CIADL tasks. The tasks ‘sweeping’ and ‘taking out garbage’ also appeared together with FM and BADL. Moreover, the tasks ‘use of sharp utensils’, ‘stovetop use’ and ‘microwave use’ showed themselves together with PIADL.