The role of basic health insurance on depression: an epidemiological cohort study of a randomized community sample in Northwest China

Major depressive disorder is a serious and recurrent disorder linked to diminished role functioning and quality of life, medical morbidity and mortality [1, 2]. According to a recent study by the World Health Organization (WHO), the average lifetime and 12-month prevalence estimates of DSM-IV major depressive disorder were 14.6% and 5.5% in ten high-income countries and 11.1% and 5.9% in eight low- to middle-income countries [3]. China is in the period of "type-transforming", and people are facing various perplexities and problems. A large-scale mental health survey in 2009 revealed that the prevalence of mental disorders among the population aged 15 and older reached 17.5%, of which 6.7% had mood disorders, including depression [4]. The prevalence of depression among the senior population in rural areas of central China was 6% [5]. The rate was 24.8% (CES-D scores >16) among university students in Beijing, 8.9% of whom were severely depressed (CES-D scores >25) [6]. The high prevalence of mental disorders has become a serious public health problem and requires health policy support from the government.

Many studies have shown that access to health insurance improves physical health status. Examples include decreased death rates [7], shortened decision times required to receive emergency services [8], and increased utilization of medical services [9]. Studies have also shown that the lack of health insurance can worsen the health of breast cancer patients [10].

Few studies have explored the correlation between health insurance and mental health, and study conclusions are contradicting. Studies in the U.S. found that mandatory health insurance coverage of mental health services is not an effective means of improving mental health outcomes [11] or reducing the suicide rate, which is a primary indicator of mental health [12]. A contradictory result was found in a survey among 513 hospital inpatients in China, which revealed that those without health insurance had a higher risk of depression [13]. These differences may be due to the different cultures and health insurance systems.

In China, the universal and affordable health care system in urban cities is the Basic Health Insurance system, including the Urban Employee Basic Health Insurance Scheme (BHIS) and Urban Resident Basic Medical Insurance (URBMI). The BHIS was established in 1998 [14] and targets urban employees of the government and other public institutions, public and private enterprises and joint ventures with foreign companies [15]. The URBMI mainly covers those who are not officially employed, the elderly, students, and underage children. Since 2007, the URBMI has been operated under a pilot program in 79 cities [16]. In sum, the Basic Health Insurance system offers low-cost health insurance for urban residents. All the premiums are divided into two parts: social pooling and individual accounts. The enrolled employees and residents only need to contribute an affordable 2% of their monthly payroll to the pool fund to access basic health insurance, regardless of age, religion, sex and socioeconomic status [17]. Over 23.734 million people participated in the BHIS, and over 19.472 million people participated in URBMI by the end of 2010 [18].

Few longitudinal community sample studies have focused on the influence of health insurance on mental disorders, such as depression and few studies explore the relationship between BHIS and mental health in China. This study intends to fill this gap and provide information to identify the relationship between the risk of depression among the Chinese and their Basic Health Insurance coverage.

This study assesses the impact of insurance on the development of depression. The results indicate that the prevalence of depression is high in northwest China, and both health insurance and poverty (measured by Dibao) have long-term influences on depression. These findings suggest that China’s Basic Health Insurance system is a significant protective factor against depression. This research provides further empirical evidence to justify the current Chinese primary health reform strategy that seeks to increase access to Basic Health Insurance in the general population. Nonetheless, there has been a worldwide systematic discrimination against mental disorders, which resulted in an exclusion of mental disorders from some social and private health insurance, regardless of economic achievement and stage of development. Examples of this tendency include the U.S. [33], some European countries [34], and China [35]. The rapid socioeconomic transition and the consequential traditional culture change in China had significantly increased the depression among the Chinese elderly and adult population [4, 36]. Growing evidence suggests that Chinese people tend to view mental illness as a reflection of one's "inability to deal with social stress", "interpersonal conflict", or "personality deficits" [37, 38]. Depression literacy may conceal the real situation [39]. In comparison, resources for mental health are scarce and unequally allocated [40]. The WHO reported that the treatment gap for severe mental disorders was 35–50% for developed countries and 76–85% for low- and middle-income countries [41]. Chinese policymakers should value the importance of mental health and invest greater resources in the future. Accordingly, China needs to reconsider its health care and service delivery system to accommodate the rapidly increasing issue of mental health. Specifically, China may need to increase mental health insurance coverage and encourage more non-psychiatric hospitals to offer psychiatric services.

The possible reason that may explain the impact of health insurance on reducing the risk of having depression is that obtaining insurance coverage can increase one’s sense of security while reducing the financial and psychological stresses created by medical treatment. Further studies are needed to indentify more reasons that may explain the relationship between health insurance and depression in China.

Survey data indicate that those who had no insurance at baseline but acquired coverage at the second follow-up still faced a higher risk of depression. This finding possibly results from the fact that data collection was prematurely conducted after the initiation of the new health insurance policy. The Basic Health Insurance scheme was launched in the summer of 2007 but was officially put into practice in the surveyed area in September. The second follow-up survey was performed between December 2007 and January 2008, and 636 participants were new insurance enrollees, comprising up to 33.7% of the sample, which was significantly higher than the 7.4% (n = 164) participants reported at the first follow-up. The percentage of participants without insurance dropped from 52.7% at the first follow-up (December 2006) to 23.6% at the second follow-up. Thus, the majority of newly enrolled participants acquired insurance quite recently during the survey. However, it is unlikely that they had any chance of using their insurance at the time of the survey. Thus, the impact of insurance may not be apparent in the data.

This study shows that there is a high prevalence of depression in Northwest China. When 21 score was used as the cutoff point, and the positive predictive value (PPV) was 55%, the prevalence of depression in northwestern Chinese cities was 14.6-16.2%. This rate was higher than that for mood disorders in general (6.7%) [4] and depression specifically among rural residents over 55 years of age (6%) [5]. This high prevalence might partially be linked to the location in which the survey was conducted. A previous population-based epidemiological study reported that the depression prevalence is significantly higher in northwestern part of China compared with the eastern and northern parts of the country [36].

Poverty is another important risk factor for depression. In addition to the demographic and socioeconomic factors, we also considered the effects of several other indicators, including major family or personal events, economic poverty (Dibao), personal health behaviors, and physical health status (diseases within the previous four weeks), all of which are factors closely related to depression according to previous studies. The three most significant predictors of depression are health insurance status, baseline depressive status, and poverty (Dibao). All other factors showed no long-term predictive relationship with depressive symptoms. In addition, prior studies proved that poverty and its associated psychosocial stressors, such as violence, unemployment, and insecurity, were correlated with the onset of adult mental disorders [42]. Another study showed that 70% of patients with mental illness within the lowest income group did not receive treatment due to their disadvantaged financial situation [43]. The government should give priority to poverty-stricken counties and provide them with essential financial assistance.

Due to the complexity of the topic, many other factors might interfere with the research conclusions. For instance, employment status is likely to be an important intervening factor in the relationship between health insurance and depression, as 94.9% of the people with insurance were enrolled in the employment-based BHIS. A previous study demonstrated a significant association between employment and self-reported state of health [44]. The presumed impact of health insurance enrollment on depression may be weakened by the factor of employment. However, no significant correlation between employment status and depression is found in this study, which indicates that the correlation between health insurance and depression is independent of employment status.

The quality of the data collected from the survey was satisfactory. The household, instead of the individual, comprised the survey sampling unit. Households were required to have at least one member 16 years of age or older to participate. Because the majority of the surveyed households had two members older than 16 years of age, the likelihood of each adult responding to the depression questions in each household was presumably 50%. According to this sampling design, the chance of each participant of the baseline depression survey being followed up in the successive surveys was also 50%. The actual follow-up rates of the study were 54.4% and 46.3% at the two follow-ups, which were reasonably acceptable given this design. Furthermore, because sample loss was random, the list-wise approach was employed to deal with missing data [45].

In communities of northwestern Chinese cities, people without Basic Health Insurance have a higher risk of depression than those with health insurance.

^aThe number also included those who were enrolled in the Government Insurance Scheme (GIS) and Labor Health Insurance, which have been replaced by new insurance offerings in the studied areas since 2005. Some people continue to use this term for convenience, which included 64 people.

^bMore people were newly enrolled in the second follow-up survey than in the first follow-up survey because Lanzhou initiated the pilot operation of the URBMI in September 2007³⁴.

This research is sponsored by the Project 985 fund of Beijing Normal University.

In the process of data collection, the Department of Civil Affairs in Gansu province offered great support in assistance with sampling and household interviews. Dr. Ruiping Xin from Northwest Normal University organized the selection of interviewers and the data collection.