Generic and disease-specific quality of life and its predictors among Chinese inpatients with schizophrenia

Highlights

• This study examined the generic and disorder-specific QOL among Chinese patients with schizophrenia.

• Monthly income and social support were significant predictors of both generic and disease-specific QOL.

• Duration of hospital stays, support use degree, negative and general psychopathology symptoms were additional significant predictors.

• Relevant therapeutic interventions are needed to alleviate clinical symptom severity for promoting the disease-specific QOL of patients with schizophrenia.

Abstract

This study aims to describe generic and disease-specific quality of life (QOL) and its predictors among Chinese inpatients with schizophrenia. A total of 209 subjects participated in this study: 121 men and 88 women. Their ages ranged from 18 to 64, with a mean age of 33.85 (S.D.=10.84). The total scores of generic and disease-specific QOL were statistically significant, correlated with patients׳ total symptom severity scores and social support scores (all P values less than 0.01). Multiple regression analysis revealed that monthly household income and subjective social support were statistically significant predictors of generic and disease-specific QOL. Duration of hospitalization, support use degree, negative and general psychopathology symptoms were additional significant predictors of disease-specific QOL. This study suggests the importance of improving subjective social support in order to promote generic and disease-specific QOL. Controlling negative and general psychopathology symptoms and improving support use degree could additionally enhance the disease-specific QOL in patients with schizophrenia.

Introduction

Mental health problems are common. The World Health Organization (WHO) estimates that globally, 450 million people suffer from a mental or behavioral disorder, and the number of persons experiencing severe mental illness (e.g. schizophrenia, psychotic disorders) ranges from 1% to 3% (WHO, 2009). In China, it is estimated that approximately 4% of adults, or 16 million people, suffer from severe mental illness (China-CDC, National Centre for Mental Health, 2009). The estimated prevalence of schizophrenia in urban areas of China is 5.7 per 1000 population, with an estimated 6.45 million prevalent cases in total (Xiang et al., 2008). It is increasingly recognized that patients with schizophrenia experience impaired quality of life (QOL) (Ritsner et al., 2012, Adelufosi et al., 2013). QOL measures are considered to be useful information for planning and evaluating clinical interventions (Xiang et al., 2012). Research evidence also shows that QOL is a valid and useful outcome criterion among patients with schizophrenia (Karow et al., 2014).

Determinants of QOL with socio-demographic and clinical factors have been well established (Kao et al., 2011, Hsiao et al., 2012, Ritsner et al., 2012, Adelufosi et al., 2013). Certain socio-demographic factors, such as monthly household income and employment status, were found to be key predictors among Taiwanese community-dwelling schizophrenia patients (Hsiao et al., 2012). In addition, better social support independently predicted higher QOL in all domains among Chinese patients with schizophrenia (Xiang et al., 2012). Furthermore, reduced QOL can be attributed to the side effects of medication (Harvey et al., 2004).

Research also reveals that greater symptom severity of an illness is associated with decreased QOL (Kao et al., 2011). Reducing symptoms (all types) are associated with higher QOL (van de Willige et al., 2005). One study examining the correlates of QOL in an Arab schizophrenia sample found that positive symptoms were a significant correlate of perceived QOL (Zahid et al., 2010). Positive symptoms, such as hallucinations, are more strongly correlated with QOL than negative symptoms, such as fatigue and low creativity (van de Willige et al., 2005). Other major determinants of QOL in people with severe mental illness include psychopathology symptoms (Hansson, 2006), and the severity of negative symptoms (Aki et al., 2008).

Although a great deal of research has been done regarding the socio-demographic and clinical determinants of QOL in patients with schizophrenia using generic measures (Xiang et al., 2012, Adelufosi et al., 2013, Lanfredi et al., 2014), few studies have investigated these determinants using disease-specific QOL measures. As schizophrenia is a multidimensional mental illness, taking generic and disease-specific QOL into consideration could provide a clearer understanding of specific disease conditions and treatment effects in patients with schizophrenia (Millier et al., 2014). Therefore, this study׳s aim was to describe QOL using a generic and disease-specific measure, and to identify QOL predictors in Chinese adults with schizophrenia, one week before discharge from hospital. Understanding the correlations of socio-demographic and clinical factors with generic and disease-specific QOL in schizophrenia could facilitate the development of relevant strategies to improve patients׳ QOL.