Toward Meeting the Needs of Homeless People with Schizophrenia: The Validity of Quality of Life Measurement

et al. (2013) Toward Meeting the Needs of Homeless People with Schizophrenia: The Validity of Quality of Life Measurement. PLoS ONE 8(10): e79677. doi:10.1371/journal.pone.0079677 Toward Meeting the Needs of Homeless People with Schizophrenia: The Validity of Quality of Life Measurement Pascal Auquier 0 Aurelie Tinland 0 Cecile Fortanier 0 Anderson Loundou 0 Karine Baumstarck 0 Christophe Lancon 0 Laurent Boyer 0 Xiang Yang Zhang, Baylor College of Medicine, United States of America 0 1 Aix-Marseille University, EA 3279 Research Unit , Marseille , France , 2 Department of Psychiatry, Sainte-Marguerite University Hospital , Marseille , France , 3 Department of Public Health, University Hospital , Marseille , France Objective: To provide new evidence regarding the suitability of using quality of life (QoL) measurements in homeless people with schizophrenia, we assess the acceptability and psychometric properties of a specific QoL instrument (SQoL 18) in a population of homeless people with schizophrenia, and we compare their QoL levels with those observed in non-homeless people with schizophrenia. Methods: This multi-centre prospective study was conducted in the following 4 French cities: Lille, Marseille, Paris and Toulouse. Two hundred and thirty-six homeless patients with schizophrenia were recruited over a 12 monthperiod. The S-QoL 18 was tested for construct validity, reliability, external validity and sensitivity to change. The QoL of the 236 homeless patients was compared with 236 French age- and sex-matched non-homeless patients with schizophrenia. Results: The eight-factor structure of the S-QoL 18 was confirmed by confirmatory factor analysis (RMSEA = 0.035, CFI = 0.95, GFI = 0.99 and SRMR = 0.015). Internal consistency, reliability and sensitivity to change were satisfactory. External validity was confirmed via correlations between S-QoL 18 dimension scores and SF-36, symptomatology and recovery scores. The percentage of missing data did not exceed 5%. Finally, homeless patients had significantly lower QoL levels than non-homeless patients with schizophrenia. Conclusions: These results demonstrate the satisfactory acceptability and psychometric properties of the S-QoL 18, suggesting the validity of QoL measurement among homeless patients with schizophrenia. Our study also reported that QoL levels in homeless patients with schizophrenia were dramatically low, highlighting the need for new policies to eradicate homelessness and tackle poverty. - Competing interests: The authors received funding from a commercial source, Janssen Pharmaceutical Companies, but this does not alter their adherence to all the PLOS ONE policies on sharing data and materials. Homelessness is an increasing problem among people living with schizophrenia [13]. Schizophrenia is over-represented in homeless populations when compared to non-homeless populations. Indeed, the prevalence of the condition is estimated to be 11% (range 416%) [4]. The management of patients with schizophrenia is particularly challenging because this sub-population of the homeless is among the most vulnerable and hardest to reach [5,6]. This group has multiple health problems, including alcohol and substance abuse disorders as well as chronic illnesses, e.g., human immunodeficiency virus, hypertension, and diabetes [7]. Treatment adherence and continuity of care in this population tends to be quite poor, and the already limited access to appropriate care [8] noted in this population is exacerbated by self-neglect and fear of being institutionalised [9]. They also have greater problems with employment, social relationships and family relationships than homeless people who do not suffer from mental illness [1012]. Accurate and appropriate assessment of health status is critical to determining the efficacy of treatment and more globally to medico-social programs and policies among homeless patients with schizophrenia. One difficulty is the presence of relevant indicators that take into account the complexity of these populations health problems and needs. Quality of life (QoL) measurements are of the utmost importance for evaluating treatment and managing care in patients with schizophrenia and offer a more global and comprehensive assessment of health status than traditional indicators (i.e., symptomatology scales) [1316]. QoL might encompass numerous dimensions for homeless patients with schizophrenia, e.g., psychological status, functional abilities, personal well-being, social interaction, economic status, vocational status and physical health [17]. However, QoL measures have been rarely validated with homeless populations [18]. The limited access to care of homeless explains that they are not well represented in validation studies conducted in health care settings. Moreover, the lack of insurance coverage of homeless does not allow them to participate to studies in some countries. The extent to which QoL measurement remains relevant and valid for homeless patients is a crucial issue that has been insufficiently examined. To our knowledge, only two studies have explored this issue in homeless people [19,20]. These studies provided evidence that QoL questionnaires could be reliable/valid measures of health status among the homeless. However, these studies 1) did not specifically consider homeless patients with schizophrenia (only 18 individuals of the 250 studied suffered from schizophrenia in the study by Garcia-Rea et al. [19]); 2) studied generic QoL questionnaires (WHOQOL-100 [19] and SF-36 [20]); 3) did not report how the factorial structure described in the sample fit with the initial structure of the tested instrument, which is a key point when considering validity in these specific populations, who were not included in the development of questionnaires [21,22]; and 4) did not explore the sensitivity to change of the instruments, which is one of the most essential requirements of an outcome measure [13,23]. In this study, we hope to provide new data regarding the suitability of QoL measurements among homeless people with schizophrenia. To this end, we propose to assess the acceptability and the psychometric properties of a specific QoL instrument (the Schizophrenia - Quality of Life short-version questionnaire: S-QoL 18 [13,24]) in a population of homeless patients with schizophrenia and we compare their QoL levels with those observed in non-homeless people with schizophrenia. Study design and population This multi-centre prospective study was conducted in the following 4 French large cities: Lille, Marseille, Paris and Toulouse. The inclusion criteria were as follows: age over 18 years; absolutely homeless (i.e., no fixed place to stay for at least the past 7 nights with little likelihood of finding a place in the upcoming month) or precariously housed (i.e., housed in single room occupancy, rooming house, or hotel/motel as a primary residence AND in the past year have a history of 2 or more ep (...truncated)