It has been shown that approximately 30–40% of patients with mental illness including schizophrenia have several clinically severe episodes during their long course of illness in Europe.16,17 Meanwhile, the relapse rate of schizophrenia has been reported to be 50–60% within 5–6 years in Japan.18,19 The majority of these patients are rehospitalized, indicating that rehospitalization is very common for schizophrenic patients in Japan. However, there have been very few studies on the risk factors of rehospitalization and the efficacy of community care in schizophrenic patients in Japan.
Risk factors of rehospitalization
The multiple logistic regression analysis revealed that the pattern of psychiatric treatment is associated with rehospitalization. Those who did not visit clinics in the second month prior to the entry and those who visited clinics more frequently than five times in the previous month were liable to readmit to the hospitals. These results may be interpreted such that absence of clinic visit induces clinical exacerbation, resulting in frequent clinic visits followed by rehospitalization. Ohara et al. reported that those who changed doctors or took medication discontinuously were readmitted more significantly.9 The importance of continuous clinic visits to continuance of living in the communities was emphasized even though clinical status was steady.20 This result indicates the importance of regular clinic visits. Therefore, to prevent the irregular pattern of clinic visits, close monitoring of the number of clinic visits and use of the outreach team would be of help to those patients who are reluctant to come to the hospital.
The efficacy of the aforementioned approaches is still controversial in Europe, especially in England,21,22 where mental health service plays a major role in community care for the mentally ill. However, the community care by mental health services has not been developed sufficiently in Japan, and the aftercare for those who are discharged from psychiatric hospitals is mostly organized by the outpatient units in the hospitals. The close monitoring of clinic visits or outreach by nurses are mostly hospital-based. Therefore, these approaches may produce outcomes that are different from those in Europe, especially England.
Interestingly, the utilization of the day-care unit at the public health center and workshops in the community were related to rehospitalization. Presumeably, when patients attending these facilities deteriorate clinically, the staff have few choices other than to advise them to visit an outpatient clinic or to admit to hospital, which then leads to rehospitalization. There are options other than rehospitalization such as home visits by public health nurses. Although these systems are not functioning well at present, they should be integrated with medical approaches.
Junior high school graduation as education level was revealed to be another risk factor of rehospitalization. In other words, educational level is an important factor in secondary prevention of schizophrenic episodes. While most Japanese go to senior high school, those who did not enter senior high school or those who quit senior high school were at risk of rehospitalization in the present study. It is possible that this reflects a problem of social function such as school refusal or being the object of bullying, as well as being a problem of intelligence. This social dysfunction may be ascribable to a premorbid state or onset of schizophrenia. From a point of view of primary prevention, the early detection of this population is required because treatment delay may affect the course of schizophrenia. In the study by Johnstone et al., untreated illness was the strongest predictor of relapse.23 Moreover, Loebel et al. showed that the time to remission as well as the degree of remission were closely related to duration of untreated psychosis when other prognostic variables were controlled.24 As stated by Birchwood et al., these findings may be the result of type of illness (those with an inherently high risk of relapse may include symptoms that delay treatment) or the result of psychosocial disruption arising from a long period of untreated psychosis.25 In the present study, age of onset and type of schizophrenia were not related to rehospitalization, suggesting that psychosocial disruption resulting from untreated illness is more important than type of illness in influencing the course of schizophrenia including rehospitalization. Therefore, we suggest that early intervention is important for those who show any signs during school age. The education level itself, however, would not be a modifiable factor. We should intervene to expose such vulnerable people to a better social experience.
Poor medication compliance was not significant in the multivariate analysis, although previous studies by Sullivan et al. and Corrigan et al. revealed it to be a strong indicator of rehospitalization.26,27 One may wonder if there is a limitation in the way we assessed compliance (i.e. the use of compliance scale of Kemp et al.13). However, as pointed out by Kemp et al., there are problems associated with more direct measures.13 Urine tests may overestimate compliance when drugs have a long half-life. Serum assays are invasive and are of limited value in assessing partial compliance. Pill counts are widely considered a useful measure but this method has a potential for dissimulation and inaccuracy.
Sullivan et al. indicated that non-compliance was associated with lack of insight (i.e. denial of mental illness), a history of fewer outpatient appointments, and being single.26 In another study the most powerful indicators of compliance were reported as being a good attitude to treatment and insight into illness.28 The average age of the patients in the study by Sullivan et al. study was 34.5 years,26 which is younger than that in the present study by more than 10 years. Taking this age difference into account, it is suggested that the subjects in our study accepted the illness and took medication, in comparison with the patients of Sullivan et al. In further studies, not only the therapeutic behaviors as evaluated in the present study but also the attitude toward medication therapy including insight into the illness, should be examined.
Incidentally, poor medication compliance was associated with rehospitalization in the bivariate analyses. Because compliance was moderately correlated with the present GAF scores (r = 0.31), the possibility that controlling the latter factors produced the negative result in the multivariate analysis cannot be excluded entirely.
We asked the subjects if they experienced life events in the past 3 months. On the interview we categorized the life events according to axis IV in DSM-IV, which was developed to describe patients in a biological, psychological and social model in a clinical situation. The answers to this question may reflect subjective experience of the interviewees. Because we employed the stress–vulnerability model of schizophrenia, in which stress plays an important role in understanding the episode of schizophrenia, the results of this life event are still informative for risk factors of rehospitalization.
In the multiple logistic regression models, life events did not remain at a significant level. The previous study suggested that life events were associated with relapse irrespective of the compliance problem,29 although it was not clear as to which domain of life events was more influential. Many of the life events in the present study were problems in the primary support group, especially families. These may be the results of patient–family interactions such as over-involvement in patient symptoms or an excess burden of patient care. According to the study by Tanaka et al., emotions of the family influence the course of schizophrenia.30
Finally, because the present study was conducted with a case–control design, we could not clarify the causal relationship. A further prospective study should be conducted to elucidate the causal relationship between the factors presented here and rehospitalization of schizophrenic patients.