Table 5.
Publications on the relationship of functional capacity (FC) with real-world functioning (RWF).
| Publication name [Quality] | Type of publication | Sample size/No. of studies (total sample size) | Population | Cognitive domains assessed | Functioning domains assessed | Key results |
|---|---|---|---|---|---|---|
| Halverson 2019 [Q = High] | SLR with meta-analysis | Total studies: 166 (n = 12,868) | SCZ spectrum disorders | NC and SC | Domains: social, occupational, independent living (FC and RWF) |
ES for the association of cognition with functioning were generally larger for FC domains than RWF domains. Cognition and FC: The ES (ûp) was 0.28 (95% CI, 0.22 to 0.33) for ‘social problem solving’ and 0.25 (95% CI, 0.22 to 0.28) for ‘social skills’ Cognition and RWF: The ES (ûp) was 0.20 (95% CI, 0.17 to 0.24) for ‘community functioning’ and 0.17 (95% CI, 0.10 to 0.25) for ‘social behavior in the milieu’. |
| Green 2004 [Q = NA] | Narrative review | Total studies: 18 (NA) | SCZ | Only NC | Domains: social, occupational, independent living (Only RWF) |
FC refers to the ability to perform certain tasks and is considered to be a proximal measure (i.e. ‘closer’ to cognition), and is therefore more directly sensitive to changes in cognition. Community functioning (RWF) is a more distal construct (i.e. further away from cognition). FC indicates what a person can do, as opposed to RWF which is a measure of what he or she actually does. Good performance on a measure of FC suggests that the person probably could perform that task in the community if they had the appropriate motivation and opportunity. |
| Harvey 2019a [Q = 7/9] | CS | 312 | SCZ, SAD | Only SC | Domain: social (FC and RWF) |
In patients with lower severity of negative symptoms, SC significantly predicted social functioning. In patients with greater negative symptom severity, FC, and not SC, predicted social functioning. |
| Harvey 2019b [Q = 7/9] | CS | 158 | SCZ | Only NC | Domains: social, occupational, independent living (FC and RWF) |
Poorer functioning on the VR tasks was associated with poorer cognition and poorer vocational functioning. |
| Galderisi 2018 [Q = 9/9] | CS | 740 | SCZ | NC and SC | Domains: social, occupational, independent living (FC and RWF) |
In the network analysis, FC and RWF had the most central role in the inter-relationships across multiple variables in schizophrenia. FC bridged cognition with RWF. |
| Cardenas 2013 [Q = 6/9] | CSa | 97 | SCZ | NR | Domains: social, occupational, independent living (FC and RWF) |
When self-efficacy was high, FC was associated with RWF. When self-efficacy was low, FC was not associated with RWF. |
| Heinrichs 2010 [Q = 7/9] | PCS | 127 | SCZ, SAD | Only NC | Domains: occupational, independent living (FC and RWF) |
Hierarchical regression analyses were conducted to assess the relation of cognition and functioning. Addition of FC to cognition yielded significant increase in validity only for concurrent and not for subsequent RWF. |
| Harvey 2013 [Q = 7/9] | PCS | 195 | SCZ, SAD | Only NC | Domain: independent living (Only FC) |
The ability to perform cognitively challenging tests, either for NC or FC was statistically unidimensional. The results implicated a single ability factor that was stably related to both neuropsychological and FC test performance; and raised the question of whether cognitive abilities, measured by neuropsychological tests and FC instruments, were tapping a single ability construct. |
CI, confidence interval; CS, cross-sectional study; ES, effect size; FC, functional capacity; NA, not applicable; NC, neurocognition; NR, not reported; PCS, prospective cohort study; Q, quality; RWF, real-world functioning; SAD, schizoaffective disorder; SC, social cognition; SCZ, schizophrenia; SLR, systematic literature review; VR, virtual reality.
a
Cross-sectional analysis of an RCT.