Decomposing disparities in the utilization of basic public health services between locals and internal migrants in China: the role of social determinants

Abstract

Background

Internal migrants in China have long been at a disadvantage in terms of access to publicly financed services, as well as the utilization of public health services. The aim of the study was to examine inequities in the use of basic public health services between internal migrants and the local population and estimate the factors that contributed to inequity in use.

Methods

The data for this study was derived from the 2017 wave of the China Migrants Dynamic Survey. Basic public health services utilization was measured by the establishment of health records, health education and chronic disease management. We performed multivariable logistic regressions to examine inequities in the utilization of basic public health services between locals and internal migrants, and Oaxaca-Blinder decomposition was used to explore possible explanations for such inequities between the two groups.

Results

A total of 27,998 cases were included in the analysis. We found that the utilization rates for establishment of health records, health education and chronic disease management among internal migrants were 71.3%, 49.2% and 65.7% lower than their local counterparts, respectively. The decomposition results indicated that the inequities in the establishment of health records between locals and internal migrants were mainly explained by whether people had heard of the National Basic Public Health Services Program (NBPHSP) (17.67%) and by health insurance (5.99%). The contributors to the inequities in health education between locals and internal migrants were community involvement (14.71%) and whether people had heard of the NBPHSP (13.89%). The main factors contributing to the difference in utilization of chronic disease management between the two groups were whether people had heard of the NBPHSP (14.49%) and community involvement (8.43%).

Conclusions

To reduce inequities in the utilization of basic public health services between locals and internal migrants, measures need to be taken to improve knowledge about the basic public health services and to help migrants integrate into the local community.

Introduction

Achieving universal health coverage (UHC) was one of the goals set by countries around the world when they adopted the Sustainable Development Goals in 2015 [1]. UHC conveys the aim that everyone should have access to quality health care when and where they need it, without financial hardship [2]. However, the resources available in every country to provide health care to its citizens are limited, and it is impossible to meet all the health needs of every individual. To achieve UHC, the essential package of healthcare services (EPHS) has been recognized as an effective approach, especially in low- and lower-middle-income countries [3].The EPHS is an approach that concentrates scarce resources on the interventions that provide the best value for money [4]. The government determines and prioritizes services according to disease burden, economic level, equity, and political reasons and ensures that these services are accessible to all those who need them [5].

Some countries have developed their own public health service programs, such as the 10 ‘essential public health services’ in the United States [6]. Ethiopia launched the “Essential Health Services Package of Ethiopia” in 2019 [7]. China has also begun to implement the Basic Public Health Service Program in 2009 [8], which currently consists of 14 basic public health service items. This program is a package of basic public health services provided free of charge to all residents by the Government of China in response to the major health problems that exist in urban and rural areas, including health record management, health education, vaccination services, child health management, maternal health management, elderly health management, chronic disease management, health management for mental illness, tuberculosis (TB) prevention and control, infectious disease and public health event reporting, traditional Chinese medicine (TCM) services, health and family planning supervision and auxiliary services, provision of free contraceptives, health literacy promotion. The funds required to carry out the services are mainly provided by the government, and both urban and rural residents can benefit from the program. To date, the program has yielded some initial positive results. Studies have indicated that the Basic Public Health Services Program has increased maternal and neonatal health service utilization and reduced maternal and neonatal mortality [9, 10]. Some basic public health services (BPHS) may not directly affect the health of the population, but the use of these BPHS would be necessary for primary care providers to offer a continuum of preventive services and health management. For example, the establishment of health records helps medical institutions monitor the health status of the population and carry out preventive and medical services in general practice. Health education enhances the health literacy of the population and helps people to manage their own health.

Despite the demonstrated importance of using BPHS, in the Chinese context, some vulnerable groups, such as internal migrants, still have difficulty accessing BPHS. The report of the Sixth National Health Services Survey showed that the average rate of establishment of health records in the country was 53.3% [11]. However, this figure is much lower among young internal migrants, at only 30.2% [12]. Moreover, a survey of internal migrants in China showed that only 33.9% of respondents had received health education on chronic diseases [13]. International experience has demonstrated that the underutilization of health services (including preventive services) by migrants, due to unfamiliarity with complex health systems, poor access to information, low health literacy and language barriers, poses a risk to their health [14, 15]. Moreover, internal migration has expanded rapidly in China: according to the Seventh National Census Bulletin, there were 375.8 million internal migrants by 2020, accounting for 26.6% of the whole population [16]. Like international migrants, they have long been disadvantaged in the allocation of public benefits and resources [17, 18]. Improving the utilization of BPHS among internal migrants is crucial to the realization of UHC and thus to the maintenance and promotion of the population health.

There are also fundamental inequities in the utilization of BPHS by internal migrants. Some studies have shown that inequities in the utilization of BPHS exist between different regions; the central and western regions were more likely to utilize BPHS than the eastern region [19, 20]. A study conducted in Shanghai found an imbalance in the utilization of BPHS between urban and suburban areas [21]. Even when living in the same area, there were significant inequities in the utilization of BPHS between locals and internal migrants [22]. In order to promote equity, in 2010 the government published guidelines for the equalization of BPHS, which aim to weaken the household registration system and emphasize that internal migrants should have access to the same public health services as the local population [23]. A pilot project was started in 2014 [24] and has shown some success, such as a significant increase in the establishment of health records and the utilization of health-care services among internal migrants [25, 26]. Existing studies have investigated inequities in the utilization of BPHS among locals and internal migrants in specific regions [27]. However, a limited number of studies have examined whether and to what extent there are inequities in the utilization of BPHS between locals and internal migrants nationwide.

Most of the existing studies have been conducted from a macro-policy perspective, to identify the factors contributing to the differences in utilization of BPHS between locals and internal migrants. It is widely accepted that the household registration system (hukou) contributes to inequities in the utilization of BPHS between the two groups [28]. It is also hypothesized that the root cause of internal migrants’ inability to access the same public health services as the local population lies in the absence of adequate financial support mechanisms [29]. In addition, the level of economic development of the destination city was probably a contributor to the differences in the utilization of BPHS between locals and internal migrants [30]. Little is known about the social determinants that contribute to inequities between internal migrants and local populations in the utilization of BPHS.

The purpose of this study was to explore inequities in the use of BPHS between internal migrants and the local population, and to decompose such observed inequities into their constituent components. The results of this study have important practical implications. To identify factors determining the utilization of BPHS that significantly contribute to inequities between locals and internal migrants could help to develop proper policies and interventions to address these issues.

Data and methods

Data source and sample

Individual-level data were drawn from the 2017 wave of the China Migrants Dynamic Survey (CMDS). The CMDS offers nationally representative data on internal migrants and has been carried out annually by the National Health Commission since 2009. The survey covers 31 provinces (autonomous regions and municipalities) as well as the Xinjiang Production and Construction Corps. This survey adopted a stratified, multi-stage, and probability proportion to size sampling (PPS) method [31]. The sample consisted of internal migrants aged 15 years and over. The total survey sample size was over 170,000 and involved about 450,000 household members.

Data from 2017 CMDS thematic surveys were used in this study. Eight cities were selected for thematic surveys, including Suzhou City, Jiangsu Province; Qingdao City, Shandong Province; Zhengzhou City, Henan Province; Changsha City, Hunan Province; Guangzhou City, Guangdong Province; Jiulongpo District, Chongqing Municipality; Xishuangbanna Prefecture, Yunnan Province; and Urumqi City, Xinjiang Autonomous Region. The sample for the thematic survey included both internal migrants and local population. A ratio-based approach was used to determine the urban local population to be surveyed. There was a 1: 1 match (on the basis of the same sex and the same age) between internal migrants and local residents who were surveyed. The questionnaire asked participants about their demographic and socioeconomic characteristics, including their intention to stay, health status and use of publicly funded services. Finally, our analysis included a total sample of 27,998 that was comprised of 13,998 internal migrants and 14,000 local residents. The distribution of the samples in each province is shown in Fig. 1.

Fig. 1

The sample size and sample distribution

Theoretical framework and measurements

We adopted Andersen’s Behavioral Model to identify the key factors in accounting for inequities in the use of health services. The model was originally developed by Anderson to explain “how” and “why” households (or individuals) use health services. The framework suggests that an individual’s decision to use health services is driven by three main factors comprising predisposing factors, such as demographic characteristics, social structure and health belief; enabling factors, such as health insurance, time spent from home to the nearest medical institutions and social relationships; and needs-based factors, such as self-rated health and any common diseases in past years [32]. Figure 2 summaries how the Anderson framework was operationalized in the Chinese context to guide our empirical analysis of variations in health service use.

Fig. 2

The theoretical framework

Dependent variable

The primary outcome was basic public health service utilization. Basic public health service utilization was measured by three separate variables: health records establishment, health education, and chronic disease management. Health records establishment was measured by the question “Did the local community establish residents’ health records for you?“, and was set as a dichotomous variable based on respondents’ answers.

Regarding health education, respondents were asked whether they had received health education in the past year in their current village/community of residence on (a) prevention and treatment of occupational diseases; (b) prevention and treatment of sexually transmitted infections (STIs); (c) reproductive health and contraception; (d) prevention and treatment of tuberculosis (TB); (e) control of tobacco use; (f) mental health; (g) prevention and treatment of chronic diseases; (h) maternal and child health care; and (i) first aid for public emergencies. If the respondent had not received health education on any of the above, they were considered as not utilizing health education and coded as 0. Otherwise, they were coded as 1.

Regarding chronic disease management, patients who have diabetes or hypertension were asked whether they had received free follow-up assessments and health check-up services provided by local community/township health centers. Respondents could answer ‘yes’ (coded 1) or ‘no’ (coded 0).

Predisposing factors

The key independent variable was a dichotomous variable that indicated whether the respondents were locals or internal migrants. Internal migrants are defined as individuals who have lived in their current city or region for at least six months but have their household registration (hukou) in a different location. In the CMDS there were separate questionnaires for internal migrants and the local population, i.e., Questionnaire C for internal migrants and Questionnaire D for the local population. We determined the type of population based on the questionnaires that respondents answered.

We included predisposing factors as follows: gender, age (continuous variable), ethnicity, education, household income per capita monthly (continuous variable), marital status, and whether the respondent had heard of the Basic National Public Health Services program. Ethnicity was divided into two categories: minorities and Han. Education was divided into three categories: illiterate, elementary and middle, college and above. Marital status was categorized as single, married, separated or widowed. We used “having heard of the National Basic Public Health Services program” as a proxy variable for health care information.

Enabling factors

Enabling factors in our study included health insurance, time spent from home to the nearest medical institution, community involvement and integration scores. Health insurance was categorized as no insurance, urban-rural resident basic medical insurance (URRBMI), urban employee basic medical insurance (UEBMI), publicly-funded medical insurance. Time spent from home to the nearest medical institution was divided into four categories: less than 15 min, 15 to 30 min, 30 min to an hour, and more than an hour. Community involvement and integration scores were used to reflect people’s social integration. Community involvement was a dichotomous variable indicating whether a resident had participated in community activities over the past year. The integration score was obtained by summing the scores of eight items, each on a 4-point scale. The score indicates the degree of integration; for internal migrants, the higher the score, the more willing they are to integrate locally. And for locals, the higher the score, the more willing they are to accept internal migrants.

Needs-based factors

We included self-rated health (SRH) and any common diseases in the past year as needs variables. SRH was divided into three categories: good, fair, and bad. Any common diseases in the past year were measured by the question “Has the respondent had diarrhea, fever, rash, jaundice, conjunctival redness, or a cold in the past year?“, which was treated as a dichotomous variable.

Statistical analysis

In this study, continuous variables were described by means and standard deviations, and categorical variables were described by counts and frequencies. We summarized the characteristics of the total sample and compared the differences in dependent and independent variables between locals and internal migrants. The Mann-Whitney U test was used for comparison of continuous variables and the χ² test for categorical variables.

Multivariate logistic regression was used to compare differences in the use of BPHS between internal migrants and local residents. A range of variables were controlled in the logistic regression, with Model 1 controlled for predisposing factors such as gender, age, ethnic and education, while Model 2 further added enabling and needs-based factors, including health insurance, time spent from home to the nearest medical institution, community involvement, integration scores, SRH and any common diseases in the past year. The results of multivariate logistic regressions are given as odds ratios (ORs) [33] and 95% CIs.

We applied the Blinder–Oaxaca decomposition to analyze disparities in the utilization of BPHS between internal migrants and the local population and estimate the proportionate contribution of each independent variable to these disparities. The Blinder–Oaxaca decomposition was originally used in labor economics [34] and has subsequently has been widely used in health economics. The technique decomposes the mean predicted difference between two groups into endowment effects (explained part) and coefficient effects (unexplained part), and estimates the contribution of each independent variable to the differences [35]. Since our dependent variables are dichotomous variables, logistic regression models were fitted to the two groups separately.

$$\:{Y}^{L}=F\left({{x}_{i}}^{L}{\widehat{B}}^{L}\right)$$

(1)

$$\:{Y}^{M}=F\left({{x}_{i}}^{M}{\widehat{B}}^{M}\right)$$

(2)

Where the superscript L denotes the local population and M denotes the internal migrants. $\:F$ is the cumulative distribution function of the logistic distribution. $\:{x}_{i}$ is a set of independent variables, and $\:\widehat{\beta\:}$ are the estimate of the corresponding coefficients. Based on Eqs. (1) and (2), the decomposition can be written as:

$$\eqalign{{{\bar Y}^L} - {{\bar Y}^M} & = \left[ {\sum\nolimits_{i = 1}^{{N^L}} {{{F\left( {{x_i}^L{{\hat B}^L}} \right)} \over {{N^L}}}} - \sum\nolimits_{i = 1}^{{N^M}} {{{F\left( {{x_i}^L{{\hat B}^M}} \right)} \over {{N^M}}}} } \right] \cr & + \left[ {\sum\nolimits_{i = 1}^{{N^M}} {{{F\left( {{x_i}^M{{\hat B}^L}} \right)} \over {{N^M}}}} - \sum\nolimits_{i = 1}^{{N^M}} {{{F\left( {{x_i}^M{{\hat B}^M}} \right)} \over {{N^M}}}} } \right] \cr}$$

(3)

Where $\:{N}^{L}$ ($\:{N}^{M}$) is the sample size of the local population (internal migrants). $\:{\stackrel{-}{Y}}^{L}-{\stackrel{-}{Y}}^{M}$ refers to the mean predicted differences in basic public health service utilization between locals and internal migrants. The first term in parentheses is the part of the gap in health service utilization that is due to differences in the observable variables, also known as the explained part. The second term is the unexplained part, which is the part of the gap that is due to differences in the coefficient. It also includes the part of the gap due to differences in unobserved variables. We did not focus on the unexplained part in this study as it is difficult to interpret accurately [36] and the results of the detailed decomposition of the unexplained part are only meaningful for variables with natural zeros [37]. Moreover, following Neumark [38] and Oaxaca and Ransom [39], we used the nondiscriminatory coefficient estimates ($\:{\beta\:}^{*}$) from the pooled regression over both groups. And the contribution of each independent variable ($\:{x}_{j}$) to the gap is computed as:

$$\eqalign{\>{1 \over {{N^M}}}\sum {\>_{i = 1}^{{N^M}}} & F(x_{ji}^L\beta \>_j^* + \sum {{\>_{J \ne \>j}}} x_{ji}^L\beta \>_j^*) \cr & - F(x_{ji}^M\beta \>_j^* + \sum {{\>_{J \ne \>j}}} x_{ji}^L\beta \>_j^*) \cr}$$

(4)

We tested the robustness of the results by using the Shapley decomposition [40] and deleting the sample of inter-provincial migrants. All analyses were performed in Stata17.0 and P < 0.05 was considered statistically significant.

Results

Participant characteristics

The basic characteristics of the sample are presented in Table 1. This study included 27,998 participants, of whom 13,998 (50%) were internal migrants and 14,000 (50%) were locals. There were 13,663 females, accounting for 48.8%. The mean (SD) age was 35.21(10.19) years. (Since gender and age were matched between the two groups, these values were very similar.) Among the internal migrants, slightly fewer had minority ethnicity (9.76% vs. 11.81%). Educational attainment was lower among internal migrants than locals, with fewer internal migrants completing college or higher education. The household income per capita monthly was 2670.18 yuan. The income of the local population was slightly higher than that of the internal migrants. Most participants (77.34%) were married, with a significantly higher proportion among internal migrants (79.57%) compared to locals (75.12%). Having heard of BPHS was significantly higher among locals compared to internal migrants.

Table 1 Descriptive statistics of key variables

With regard to the enabling resources, there was a significant difference in the distribution of health insurance types between the locals and internal migrants, the internal migrants had a higher proportion of individuals without insurance and URRBMI compared to the locals. The proportion of the internal migrants with a time of less than 15 min from home to the nearest medical institution was slightly lower than that of the locals. Community involvement of the internal migrants (46.68%) was significantly lower than that of the locals (67.06%). Integration scores were significantly higher for the internal migrants than for the locals.

As for the needs, 84% of people were in ‘good’ health, no significant difference between locals and internal migrants. The prevalence of common diseases in the previous year was higher among internal migrants (64.67%) than locals (63.22%).

Figure 3 illustrates the utilization of BPHS by locals and internal migrants. We found that the local population had a significantly higher rate of utilization than the internal migrants in the establishment of health records, health education and chronic disease management (P < 0.001). In terms of the types of BPHS, health education had the highest rate of utilization, and the establishment of health records and chronic disease management had a lower rate of utilization.

Fig. 3

The utilization of basic public health services by locals and internal migrants

Multivariable logistic regression results

The results of multivariable logistic regression are reported in Table 2. In Model 1, internal migrants showed a lower utilization rate than local populations for establishing health records, health education, and chronic disease management. After adjusting for enabling resources and needs variables, the utilization rates of the internal migrants for the establishment of health records, health education and chronic disease management were 71.3%, 49.2% and 65.7% lower than their local counterparts, respectively (Model 2).

Table 2 Association of independent variables with the utilization of basic public health services

Several variables also significantly predicted the utilization of BPHS in the logistic regression. Specifically, Individuals with elementary and middle school education, married, covered by UEBMI, lived more than one hour from the nearest medical institution, or reported higher integration scores were more likely to establish health records and access health education. Older adults were more likely to establish health records and participate in chronic disease management. Additionally, individuals with a college education or above and those who were separated or widowed were more likely to utilize health education. However, higher income was linked to lower utilization of health education. Moreover, female, minorities, having heard of the NBPHSP, ‘good’ self-rated health, being insured under URRBMI and publicly-funded medical insurance, and more community involvement were associated with increased utilization of both BPHS.

Blinder–Oaxaca decomposition results

There were substantial differences in the use of BPHS between locals and internal migrants. To explore the sources of these differences, we decomposed the predicted differences using the Blinder-Oaxaca decomposition of the logistic model. As shown in Table 3, the mean predicted probability of establishment of health records were 0.691 and 0.369 for the locals and internal migrants, respectively. Thus, there was a mean difference of 0.323 (32.3%) between the two groups. The decomposition results indicated that the independent variables in Model 2 explained 27.64% of the disparities in the utilization of BPHS (endowments effect), 72.36% of the disparities was due to unobservable and unmeasured variables, as well as possible discrimination (coefficients effect). Similarly, the difference in health education between locals and internal migrants was 0.157, 31.85% (0.050) of the difference is explained by observable variables, and the remaining 68.15% (0.107) of the difference is due to coefficient differences. The total difference in chronic disease management between locals and internal migrants was 0.267, with 22.85% of the differences were attributed to observed variables and 77.15% of the difference were attributed to unmeasured variables.

Table 3 Decomposition results

Figure 4 visualizes the contribution of each independent variable to the differential utilization of BPHS between locals and internal migrants, and detailed results can also be found in Supplementary Table 2. Ethnicity, having heard of the NBPHSP, common diseases in the previous year, health insurance, community involvement and integration scores had significant contributions to the inequities in establishment of health records between the two groups. Among them, having heard of the NBPHSP contributed the most. Specifically, equalizing the number of people who have heard of the NBPHSP would be expected to reduce the gap in the establishment of health records between the two groups by 17.67%. Health insurance and community involvement contributed 5.99% and 4.07%, respectively. Integration scores (-0.41%, p < 0.001) reduced the disparities between the two groups. That is, if the integration scores of the internal migrants are reduced to the level of the local population, it would increase the difference by 0.41%.

Fig. 4

Contribution of each independent variable to the total differences

In terms of health education, the biggest contributors to the difference in utilization between locals and internal migrants were community involvement (14.71%, p < 0.001) and having heard of the NBPHSP (13.89%, p < 0.001). Integration scores and marriage reduced the differences between the two groups.

Having heard of the NBPHSP (14.49%, p < 0.001) was the biggest contributing factor to the difference in utilization of chronic disease management between the two groups, and community involvement (8.43%, p < 0.001) was another important factor in the difference in utilization of chronic disease management.

Robustness checks

First, we employed the Shapley decomposition to analyze the contributing factors to the inequities in the utilization of BPHS between internal migrants and local population. The contributing factors to the differences in the establishment of health records and health education were consistent with the main results, and there was a slight difference in the main contributing factors for chronic disease management (Supplementary Table 3). Furthermore, previous study has shown that inter-provincial mobility has a negative effect on social integration [41], we test the robustness of the results by excluding inter-provincial migrants. We repeated the Blinder–Oaxaca decomposition after deleting the sample of inter-provincial migrants, the main results remain the same (Supplementary Table 4).

Discussion

Based on the nationally representative data on China’s internal migrants, we explored the inequities in the utilization of BPHS between the internal migrants and local populations, and provided an in-depth analysis of the contribution of each independent variable to the differences using Blinder–Oaxaca decomposition. We demonstrated that the utilization of BPHS was lower among the internal migrants compared to the local population. The differences in the community involvement and having heard of the NBPHSP were the major contributors to the utilization differences between locals and internal migrants, and the integration scores reduced inequalities in the utilization of BPHS.

Although the implementation of the “Equalization Program of Basic Public Health and Family Planning Services for Migrants” has significantly increased the utilization of BPHS among internal migrants [25], our study shows that the utilization of BPHS among internal migrants remains lower than among the local population, and this result has been confirmed in previous studies [42]. Possible reasons for the result are twofold. Firstly, from the point of view of public health service providers, under the household registration (‘hukou’) system, the government determines funding for public health services based on the number of local residents in the “hukou” area, which excludes internal migrants [43]. Despite the fact that China has been reforming the “hukou” system to reduce the barriers to public service utilization for internal migrants, it still has a negative impact [44]. In 2016, the national financing standard per capita in most provinces was $6.51, which is far below the cost of providing BPHS [45]. So providers have little funding and incentive to deliver BPHS to all populations in the area [8]. Moreover, BPHS are provided by primary health care organizations, which do not have enough well-trained public health service workers, and the large number of public health service activities and high work pressure have led to burnout among primary health care workers, which also affects the delivery of BPHS [45]. Second, from the point of view of the migrants, given their lower socioeconomic status [46], much of their time and effort was spent earning a living [47], with little attention paid to preventive health services. In this study, 36.72% of internal migrants had not heard of the BPHS program, there was insufficient knowledge of the importance of the BPHSP and how to obtain BPHS, as a result, internal migrants were less likely to use BPHS.

The factors influencing the utilization of BPHS were multifaceted and varied between different types of BPHS. Overall, those who were female, more educated, older, married, with higher integration scores, having heard of the NBPHSP, covered by health insurance and having more community involvement were more likely to use BPHS, which is consistent with findings from other studies [44, 48]. Studies assessing the relationship between income and the utilization of BPHS have produced mixed results. We found no significant association between income and the establishment of health records or chronic disease management, because BPHS in China are provided free of charge to all residents. However, higher incomes made less use of health education. Previous studies have found that higher socio-economic levels were associated with higher health literacy and health awareness [49], they already have a great deal of health knowledge and there is no need for them to participate in health education. Combined with the fact that people at higher economic levels have the resources to access higher quality health care services [50], their demand for health education services was relatively small.

Having heard of BPHSP is the most important contributor to the difference in the utilization of BPHS between locals and internal migrants. If the knowledge of BPHSP of the internal migrants were increased to the same level as that of the local population, there would be a significant increase in the utilization of BPHS among the internal migrants. According to the Knowledge-Attitude-Practice (KAP) theory [51, 52], there are three consecutive processes involved in changing an individual’s health behavior, namely, acquiring health knowledge and information, changing beliefs/attitudes, and formulating behaviors. Health care knowledge and information is the basis for developing positive beliefs/attitudes and changing health-related behaviors. Previous empirical studies have shown that increasing the awareness of BPHSP among internal migrants could promote higher utilization of BPHS [53, 54]. The lack of health policy information among internal migrants was an obstacle to their utilization of BPHSP. Hence, policies aimed at reducing disparities in the utilization of BPHS between locals and internal migrants might focus on making health policy information more widely available.

Our study highlights the importance of social integration for China’s internal migrants. Social integration is not only conducive to improving the utilization of BPHS [55], but also plays an important role in reducing the inequities in the utilization of BPHS between locals and internal migrants. The results indicated that more community involvement of migrants could reduce inequities in the utilization of BPHS between migrants and the local population. The potential mechanism may be that more community involvement of the migrant population would enhance their communication with the local population and government, which would mitigate the information asymmetry between the two groups, thereby enabling internal migrants to obtain more information related to public services and increasing their utilization of BPHS [56]. Additionally, higher integration scores for internal migrants contribute to reducing inequality. Higher integration scores implied a greater willingness to integrate locally and a stronger sense of identity with the destination city, which make people were more likely to use BPHS in the local area. However, one study has shown that the largest positive correlation between integration scores and utilization of BPHS exists in the lower economic level [57].

The findings of this study provide another perspective on the drivers of inequalities in the utilization of BPHS among locals and internal migrants, suggesting that these inequalities may be addressed through social and health policies. First, government subsidies have proven to play a crucial role in the coverage of public health services [18]. It is necessary to develop a mechanism to ensure funding of BPHS for internal migrants, providing them with the same standard of funding as the local population, thereby ensuring the supply of BPHS for them. Second, the government should do more to publicize the basic public health service program, and thoroughly advertise the contents of the basic public health service program and promote access to these services. Efforts should also be made to popularize the importance of utilizing BPHS so as to encourage the population, especially vulnerable groups such as internal migrants, to take advantage of BPHS. Thirdly, society should collaborate in improving both their objective integration (e.g., access to employment, housing, healthcare, and education) and subjective integration (e.g., feelings of belonging, social connections, and psychological well-being). The Government should take the internal migrants into account when formulating health policies. Communities can provide more social services to offer support and assistance to internal migrants. Migrants should also take the initiative to integrate into the destination city; they can take part in more social and voluntary activities, strengthen their communication with the local population and build up their interpersonal networks.

Our study also has some limitations. First, this is a cross-sectional study, and the results obtained need to be interpreted with caution: limited causal inferences can be drawn. Secondly, the utilization of BPHS was self-reported and could be subject to omission or misreporting. The variable “heard of the basic public health program” may not accurately capture the respondents’ actual knowledge or familiarity with the specific details and scope of the program. Third, China’s basic public health service package contains a total of 14 types of BPHS, and in addition to the three types of public health services in this study, it also includes health management for the elderly, infants, young children, pregnant women, and so on. However, due to data limitations, we were only able to analyze the equality of utilization of these three BPHS. Further research might focus on the utilization of other types of BPHS, as well as services for priority populations. Moreover, while making every effort to promote universal coverage, attention should also be paid to the quality of BPHS. Finally, all control variables available in the database were included in the model, but it is possible that other unobserved or omitted variables may affect the results of the estimation. In particular, the unexplained part of the decomposition results contains differences explained by these omitted variables, but this part cannot be quantified.

Conclusion

There were inequalities in the utilization of BPHS between internal migrants and the local population, and internal migrants were found to be disadvantaged in the utilization of BPHS. Some social determinants contributed significantly to these differences. Specifically, having heard of BPHS and community involvement were the main contributors to the disparities, while integration scores served as a suppressor of these differences. These contributing factors derived from the analysis could be targeted for intervention in public health and policy.