We examined how internet use was associated with health in China from 2014 to 2018. Our regression analysis based on three wave longitudinal data and dynamic models with the lagged internet use variable indicated that internet use had significant positive associations with SRH, and these results on SHR were generally in line with the positive results from previous studies in China using the cross-sectional data analysis method [14–17], which did not fully control for statistical biases, and the study based on two wave longitudinal data [18]. Regarding the association between internet use and other health outcomes, which were estimated in this study for the first time, our results showed that internet use may reduce the probability of developing a mental health disorder and becoming an inpatient nationwide.
These findings can contribute to the literature on the issue of association with the internet and health outcomes from multiple perspectives. It is reported that in 2017, 792 million people lived with a mental health disorder; the proportion was 10.7%, which is slightly more than one in 10 people worldwide [29]. The World Health Organization (WHO) reported that 54 million people suffered from depression and about 41 million from anxiety disorders in China [29], and the proportion of people with mental health disorder in this country was more than 12% of that worldwide. With the exception of increasing public health care expenditure on the treatment of mental health disorders, our results suggest that policies promoting the digital economy and expanding internet penetration may contribute to improving mental health status.
Our estimation results indicated that the positive effect of internet use was modestly significant for males than for females, which may be due to the difference in internet access by gender. It is argued that a gender digital gap exists in internet access that arose in developed countries in the early stages of ICT development [31–33]. According to data from the CNNIC, the proportion of female internet users in China was 30% in 2000 and 48.1% in 2020 [1], which suggested a gender disparity in internet access in China. Additionally, the gender gap in educational attainment can lead to a gender gap in internet use skills, which may explain the difference in internet effects on health outcomes by gender. Based on the data from CFPS, in 2018, the period of schooling of individuals aged 24 and over was 8.17 years for males—longer than that (6.68 years) for females.
The results indicated disparities in internet use effects among age groups. The positive effect of internet use on health outcomes was greater for middle and older generations; this may be because the problem of addictive use (overuse) of the internet is serious in younger generations compared to other age groups as the ability to control internet addiction is weaker for teenagers than for adults [11].
Furthermore, a disparity existed in the effects of internet use among urban and rural residents. The positive effect of internet use on health outcomes was greater for urban residents than for their counterparts. The reasons for this can be explained as follows: first, the internet penetration rate is lower for rural residents than for urban residents as the development of internet infrastructure is lagged in rural areas. According to No. 45 of the Statistical Report on the Development of the Internet in China published by the China Internet Information Center, the number of internet users in China reached 989 million in June 2020, including 680 million urban residents and 309 million rural residents with internet penetration rates of 76.4% and 52.3%, respectively [1]. Second, the level of educational attainment is higher for urban residents. For example, based on the CFPS, the average period of schooling of individuals aged 24 and over was 8.84 years for urban residents and 5.98 years for rural residents in 2018. It is predicted that well-educated individuals may have a higher ability to use the internet to improve their health outcomes. The internet access/use skill gap between urban and rural residents can expand the disparity of health outcomes between the two, which may cause the problem of a severe socioeconomic status inequality [34].
Based on the results of this study, we can argue that in general, policies promoting the development of the digital economy may improve the nation’s health status. To reduce digital division problems, policies for reducing the problematic use of the internet for teenagers, promoting internet infrastructure expansion in rural areas, and reducing the gender and urban-rural gaps in internet access and education attainment should be considered by the Chinese government.