Is processing speed predictive of functional outcome in psychosis?

Department of Psychiatry and Neuropsychology, Maastricht University, P.O. BOX 616 (VIJV), 6200 MD, Maastricht, The Netherlands.
Social Psychiatry and Psychiatric Epidemiology (Impact Factor: 2.54). 07/2008; 43(6):437-44. DOI: 10.1007/s00127-008-0328-y
Source: PubMed


To investigate the contribution of processing speed in the prediction of various domains of outcome in psychosis.
Data were drawn from the UK700 Case Management Trial of 708 patients with chronic psychotic illness. Regression analyses were applied to investigate cross-sectional and longitudinal associations between processing speed at baseline and measures of service use, social outcome and subjective outcome, taking into account current psychopathology and adjusting for baseline values of the outcome measure.
Cross-sectionally, processing speed was associated with all three domains of outcome, although only associations in the social and subjective outcome domain remained significant after controlling for psychopathology and the effects differed between and within domains of outcome. Prospectively, only the subjective outcome measure of number of met and unmet needs (CAN) was weakly associated with baseline neurocognitive performance after adjustment for baseline needs. Other associations disappeared after adjustment for the baseline measure of outcome and/or baseline psychopathology.
The finding of weak cross-sectional associations in the absence of specific and unconfounded longitudinal associations suggests that processing speed is an independent dimension of disease severity rather than a causal factor impacting on social outcome. Nevertheless, longitudinal change in patient reported needs may be weakly sensitive to baseline cognitive impairment.

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Available from: Tom Patrick Burns, Sep 30, 2015
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    ABSTRACT: Intensive Case Management (ICM) is a community based package of care, aiming to provide long term care for severely mentally ill people who do not require immediate admission. ICM evolved from two original community models of care, Assertive Community Treatment (ACT) and Case Management (CM), where ICM emphasises the importance of small caseload (less than 20) and high intensity input. To assess the effects of Intensive Case Management (caseload <20) in comparison with non-Intensive Case Management (caseload > 20) and with standard community care in people with severe mental illness. To evaluate whether the effect of ICM on hospitalisation depends on its fidelity to the ACT model and on the setting. For the current update of this review we searched the Cochrane Schizophrenia Group Trials Register (February 2009), which is compiled by systematic searches of major databases, hand searches and conference proceedings. All relevant randomised clinical trials focusing on people with severe mental illness, aged 18 to 65 years and treated in the community-care setting, where Intensive Case Management, non-Intensive Case Management or standard care were compared. Outcomes such as service use, adverse effects, global state, social functioning, mental state, behaviour, quality of life, satisfaction and costs were sought. We extracted data independently. For binary outcomes we calculated relative risk (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For continuous data we estimated mean difference (MD) between groups and its 95% confidence interval (CI). We employed a random-effects model for analyses.We performed a random-effects meta-regression analysis to examine the association of the intervention's fidelity to the ACT model and the rate of hospital use in the setting where the trial was conducted with the treatment effect. We included 38 trials (7328 participants) in this review. The trials provided data for two comparisons: 1. ICM versus standard care, 2. ICM versus non-ICM.1. ICM versus standard care Twenty-four trials provided data on length of hospitalisation, and results favoured Intensive Case Management (n=3595, 24 RCTs, MD -0.86 CI -1.37 to -0.34). There was a high level of heterogeneity, but this significance still remained when the outlier studies were excluded from the analysis (n=3143, 20 RCTs, MD -0.62 CI -1.00 to -0.23). Nine studies found participants in the ICM group were less likely to be lost to psychiatric services (n=1633, 9 RCTs, RR 0.43 CI 0.30 to 0.61, I²=49%, p=0.05).One global state scale did show an Improvement in global state for those receiving ICM, the GAF scale (n=818, 5 RCTs, MD 3.41 CI 1.66 to 5.16). Results for mental state as measured through various rating scales, however, were equivocal, with no compelling evidence that ICM was really any better than standard care in improving mental state. No differences in mortality between ICM and standard care groups occurred, either due to 'all causes' (n=1456, 9 RCTs, RR 0.84 CI 0.48 to 1.47) or to 'suicide' (n=1456, 9 RCTs, RR 0.68 CI 0.31 to 1.51).Social functioning results varied, no differences were found in terms of contact with the legal system and with employment status, whereas significant improvement in accommodation status was found, as was the incidence of not living independently, which was lower in the ICM group (n=1185, 4 RCTs, RR 0.65 CI 0.49 to 0.88).Quality of life data found no significant difference between groups, but data were weak. CSQ scores showed a greater participant satisfaction in the ICM group (n=423, 2 RCTs, MD 3.23 CI 2.31 to 4.14).2. ICM versus non-ICM The included studies failed to show a significant advantage of ICM in reducing the average length of hospitalisation (n=2220, 21 RCTs, MD -0.08 CI -0.37 to 0.21). They did find ICM to be more advantageous than non-ICM in reducing rate of lost to follow-up (n=2195, 9 RCTs, RR 0.72 CI 0.52 to 0.99), although data showed a substantial level of heterogeneity (I²=59%, p=0.01). Overall, no significant differences were found in the effects of ICM compared to non-ICM for broad outcomes such as service use, mortality, social functioning, mental state, behaviour, quality of life, satisfaction and costs.3. Fidelity to ACT Within the meta-regression we found that i. the more ICM is adherent to the ACT model, the better it is at decreasing time in hospital ('organisation fidelity' variable coefficient -0.36 CI -0.66 to -0.07); and ii. the higher the baseline hospital use in the population, the better ICM is at decreasing time in hospital ('baseline hospital use' variable coefficient -0.20 CI -0.32 to -0.10). Combining both these variables within the model, 'organisation fidelity' is no longer significant, but 'baseline hospital use' result is still significantly influencing time in hospital (regression coefficient -0.18 CI -0.29 to -0.07, p=0.0027). ICM was found effective in ameliorating many outcomes relevant to people with severe mental illnesses. Compared to standard care ICM was shown to reduce hospitalisation and increase retention in care. It also globally improved social functioning, although ICM's effect on mental state and quality of life remains unclear. ICM is of value at least to people with severe mental illnesses who are in the sub-group of those with a high level of hospitalisation (about 4 days/month in past 2 years) and the intervention should be performed close to the original model.It is not clear, however, what gain ICM provides on top of a less formal non-ICM approach.We do not think that more trials comparing current ICM with standard care or non-ICM are justified, but currently we know of no review comparing non-ICM with standard care and this should be undertaken.
    Cochrane database of systematic reviews (Online) 10/2010; 10(10):CD007906. DOI:10.1002/14651858.CD007906.pub2 · 6.03 Impact Factor