Subjective quality of life in first-episode psychosis. A ten year follow-up study
Introduction
Quality of life (QoL) is an important outcome measure for patients with a first-episode psychosis (FEP) (Malla and Payne, 2005). Although still debated, the QoL-concept is most commonly regarded as both comprising a subjective part (S-QoL) measuring life satisfaction, and a more objective part (O-QoL) integrating socio-economic indicators like finances, housing and quality of social network. In line with this, the most commonly used instruments measuring QoL among patients with psychosis include both objective and subjective perspectives on QoL (Lehman, 1988, Priebe and Huxley, 1999, Oliver et al., 1997).
Previous research has primarily focused on the relationship between psychiatric symptoms and QoL. A meta-analysis of psychiatric symptoms and QoL in schizophrenia (Eack and Newhill, 2007) concluded that psychiatric symptoms have a significant, though small effect on both O-QoL and S-QoL. Looking specifically at the relationship between symptoms and S-QoL, general psychopathology (e.g. anxiety and depression) show larger effect sizes than psychotic symptoms (Eack and NewHill, 2007, Karow et al., 2014). The effects of psychiatric symptoms appear to be smaller in longitudinal than cross-sectional studies. In a large longitudinal study, changes in S-QoL were associated with changes in depressive symptoms and hostility, however only explaining 5 and 0.5% of the variance respectively (Priebe et al., 2011). Although less investigated than psychiatric symptoms, socio-economic variables like financial situation (Heider et al., 2007), social network and support (Hansson and Björkman, 2007, Ritsner et al., 2012, Vatne and Bjorkly, 2008) have also been shown to influence S-QoL. However, previous meta-analyses conclude that more longitudinal studies are needed (Eack and NewHill, 2007, Vatne and Bjorkly, 2008).
Most previous research on S-QoL in schizophrenia has been on chronic samples of patients. To reduce the effect of differences in duration of disease and treatment, more studies on FEP-cohorts are desired. Especially, there are few longitudinal studies investigating S-QoL in FEP patients. In a nine months follow-up of 51 patients with a schizophrenia-spectrum disorder, Priebe et al. (2000) reported no change in S-QoL. On the individual level, no baseline variables predicted a change in S-QoL, but change in S-QoL was significantly correlated with changes in anxiety/depression. Gorna et al. (2008) also found no significant changes, in S-QoL, in a five years follow-up study of first-episode schizophrenia patients. Cross-sectional analyses at one- and five-year follow-up showed that negative symptoms were significantly related to lower S-QoL at both time points, while more social support was significantly related to higher S-QoL at five-year follow-up. Contrary to this, two previous follow-up studies reported an improvement in S-QoL over the first two years after a FEP (Thorup et al., 2010, Melle et al., 2010). In the latter of these, the improvement was predicted by reduced score on PANSS excitative and depressive components, better global functioning, higher level of daily activities, more social contacts and better perceived general health. The same variables were related to S-QoL cross-sectionally at two-year follow-up (Melle et al., 2010).
To summarize, there is mixed evidence regarding S-QoL-development in FEP patients. One reason might be that no study has conducted longitudinal analyses using linear mixed model, which is the recommended statistical method when analyzing repeated measurements within individuals (Gueorgieva and Krystal, 2004, Field, 2013, Fitzmaurice, 2004). No study has examined S-QoL-development longer than five years, and there is a lack of longitudinal studies investigating how socio-economic factors' influence S-QoL-development. Especially, more studies investigating the association between changes in S-QoL and changes in psychiatric symptoms and socio-economic variables are needed, as this can provide valuable information about to what extent treatment can improve S-QoL. We here present a 10-year naturalistic follow-up study of FEP patients recruited at first treatment. The main aims were to 1) describe S-QoL-development the first 10 years in FEP patients, 2) investigate which baseline variables, including psychiatric symptoms and socio-economic variables (O-QoL-measures), that predict S-QoL-development and 3) investigate how changes in psychiatric symptoms and socio-economic variables (O-QoL-measures) are associated with S-QoL-development.
Section snippets
The TIPS study
The TIPS (Early Treatment and Intervention of Psychosis) study is a large prospective study of consecutively admitted FEP-patients. The study was designed to identify and follow up clinical, epidemiologic samples of FEP-patients from four Scandinavian health care sectors (North and south sector, Rogaland County, Norway, Ullevaal Sector, Oslo, Norway, and Fjorden mid-sector, Roskilde, Denmark) and to test whether early detection could improve the course of psychotic disorders. The study is
Results
Patient characteristics at baseline and 10-year follow-up are presented in Table 1.
Bivariate correlations are displayed in Table 2. S-QoL at baseline was correlated with S-QoL at 10-year follow-up. In addition, S-QoL at baseline were correlated with two measurements at 10-year follow-up; PANSS depressive component and daily activities Two baseline measures were significantly correlated with S-QoL at 10-year follow-up; PANSS cognitive component and financial adequacy.
S-QoL-development (mean
Discussion
In this 10-year follow-up study of a FEP-cohort, S-QoL improved significantly over the follow-up period. The overall improvement seems to be a result of what happened during the first five years after start of treatment. Patients with low S-QoL at baseline improve more over time than patients with higher S-QoL at baseline.
Previous follow-up studies on FEP patients have shown different patterns of S-QoL-development; some showing no improvement (Priebe et al., 2000, Gorna et al., 2008), while one
Role of funding source
The project has been approved by the Regional Committee for Medical Research Ethics Health Region II (#S-95189) and the Regional Committee for Medical Research Ethics Health Region East (#1.2007.2177).
Data Inspectorate (License #96/3017-2 and #2003/2052).
Biological data collection approved by Norwegian Directory of Health (#200403453) and the Regional Committee for Medical Research Ethics Health Region East (#493-03-01179). The Regional Committee for Science Ethics region Sjælland, Denmark
Contributors
Authors SF, TM, IM, PV, SO, BRR, JIR, JOJ, TKL, IJ, ES and UH took part in designing the study. Authors ESG, KL, JIR and SF undertook the statistical analysis of this particular study. Author ESG wrote the first draft of the manuscript. All authors contributed to and have approved the final manuscript.
Conflict of interest
All authors declare that they have no conflicts of interest.
Acknowledgments
The authors would like to thank all the patients who have contributed to this study.
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