Effect of Team Composition on Integrated Care Within Multidisciplinary Family Doctor Teams in China: Inter-Professional Collaboration as Mediator

Study setting and participants

Surveys of FDTs were conducted in Zengcheng District and Panyu District, Guangzhou city of China, in August and September 2023. A stratified random sampling approach was used to select study districts. The 11 districts of Guangzhou were classified as urban or rural based on the dominant type of primary health institutions (e.g., community health centers vs. township hospitals) operating within their administrative boundaries. Panyu District, an economically developed and highly urbanized area, and Zengcheng District, a suburban–rural transitional district, were randomly selected to represent urban and rural regions of Guangzhou, respectively.

All FDTs across 32 primary health institutions in the two districts were enrolled in the survey. Eligibility criteria included: (1) over 6 months’ operational duration; (2) capacity and availability to complete the survey; (3) provision of informed consent; (4) participation of both team leader and at least two other team members. Ultimately, 224 FDTs met these criteria and were analyzed, achieving an 80.58% inclusion rate. Table 1 showed characteristics of the teams.

According to Fritz and MacKinnon [16], a sample size of approximately 148 is required to detect small-to-medium mediation effects using bias-corrected bootstrap procedures (α = 0.05, power = 0.80). Our sample size of 224 exceeded this requirement.

Data collection

Data were collected through questionnaires comprising three sections. The first section captured organizational demographics, including team size, establishment year, team composition, and contracted residents’ enrollment size. Regarding team composition, basic teams were defined as those including only general practitioners, nurses, and public health physicians. Standard teams were defined by the addition of specialists or village doctors to the core roles. Advanced teams were defined as standard teams further integrated with additional professionals, such as TCM practitioners, TCM pharmacists, and rehabilitation therapists.

The second section employed a structured evaluation instrument to assess IPC levels within FDTs. This instrument was developed based on a previously established IPC evaluation index framework [17]. The framework encompasses five dimensions, namely shared goals and visions [15], internalization [15], formalization [18], governance [19], and incentives [20]. Each item was rated on a 5-point Likert scale. Dimension scores were calculated by summing the item scores within each dimension. Team-level IPC scores were computed as the aggregate of dimension scores. This evaluation index framework was methodologically constructed and preliminarily validated in our prior research [17]. In this study, the instrument had a Cronbach’s α of 0.688. For structural validity, exploratory factor analysis showed KMO = 0.723 (Bartlett’s test of sphericity, p < 0.001), most item factor loadings were ≥ 0.40.

The third section measured the level of IC, using a validated Chinese version of the staff IC measurement tool [21]. The IC measurement tool includes three dimensions: professional integration [22], cultural competence [23] and technical competence [24]. These dimensions are assessed via a 5-point Likert-type scale ranging from “strongly disagree” to “strongly agree”. Dimension scores were calculated by summing the items within each dimension. Team-level IC scores were derived from the average of individual member scores. In this study, the scale had a Cronbach’s α of 0.960. For structural validity, exploratory factor analysis showed KMO = 0.956 (Bartlett’s test of sphericity, p < 0.001), and all item factor loadings were ≥ 0.40.

Data analysis

Characteristics of the FDTs were described as the ordinal categorical variable (Basic/Standard/Advanced). Spearman correlation analysis was analyzed for the relationship between team composition, IPC, and IC. Before performing regression and mediation analyses, multicollinearity among independent variables was assessed by calculating variance inflation factors (VIFs) using multiple linear regression models [25]. Covariates with a VIF greater than 10 were considered to exhibit multicollinearity (see Appendix 1).

According to the method suggested by Professor VanderWeele [26], mediation analysis was conducted to examine whether IPC mediated the relationship between team composition and IC. Team composition was treated as a multicategorical variable and entered into the models using indicator (dummy) coding. Regression models were fitted to estimate the total effect of team composition on IC, the association between team composition and IPC, and the direct effect of team composition on IC after incorporating IPC into the model. All models adjusted for potential confounders, including team size, establishment year, and the ratio of contracted residents to general practitioners. Indirect effects were estimated using bias-corrected bootstrap procedures with 5,000 resamples. Mediation was considered statistically significant when the 95% bootstrap confidence interval excluded zero. The proportion mediated was calculated as the ratio of the indirect effect to the total effect. The proportion mediated was interpreted cautiously when the total effect was not statistically significant. All analyses were conducted using the PROCESS macro for SPSS 27.0.

To further examine the structural associations between the five dimensions of IPC and the three dimensions of IC, path analysis was performed using Stata 17.0. Model parameters were estimated via the maximum likelihood estimation method. The goodness-of-fit for the hypothesized models was assessed using the following indices: χ²/df < 3, Root Mean Square Error of Approximation (RMSEA < 0.08), Standardized Root Mean Square Residual (SRMR < 0.08), Goodness-of-fit Index (GFI > 0.90), Tucker–Lewis Index (TLI > 0.90), and Comparative Fit Index (CF > 0.90). All tests were two-tailed, with statistical significance set at p < 0.05.

Ethics approval

This study was approved by the Biomedical Research Ethics Review Committee of the School of Public Health, Sun Yat-sen University (Approval No. [2022] 030). Written informed consent was obtained from all participants, and the whole study process followed the Helsinki Declaration.

Characteristics for the FDTs

As shown in Table 1, a total of 224 FDTs were included in the study, of which 54.46% were standard teams, followed by advanced teams (28.13%), and basic teams (17.41%). The average establishment years of the teams was 5.37, and the mean ratio of contracted residents to general practitioners was 2269.52. The overall average score for IPC across all teams was 3.97, with higher scores in the incentive (1.19) and governance (1.11) dimensions, and lower scores in the dimensions of internalization (0.63), shared goals and visions (0.53), and formalization (0.50). For IC, the overall average score across the teams was 71.76, with the highest scores in the dimensions of technical competence (34.82), followed by cultural competence (21.48), and professional integration (15.45).

Correlation analysis of team composition, IPC and IC

As shown in Table 2, there were significant correlations between team composition and IC, and between IPC and IC (p < 0.001). However, the correlation between team composition and IPC was not statistically significant (p = 0.124).

Mediation analysis of the association between team composition and IC via IPC

Table 3 shows the mediation analysis exploring whether IPC statistically mediates the association between team composition and IC. For standard teams compared with basic teams, the total effect on IC was not statistically significant (B = 1.986, 95% CI: –0.719 to 4.691, p = 0.149). However, the indirect effect via IPC was significant (B = 1.743, 95% CI: 0.490 to 3.128), while the direct effect was not significant (B = 0.243, 95% CI: –2.157 to 2.643, p = 0.842). For advanced teams compared with basic teams, the total effect was statistically significant (B = 7.386, 95% CI: 4.316 to 10.456, p < 0.001). Both the direct effect (B = 5.351, 95% CI: 2.624 to 8.077, p < 0.001) and the indirect effect via IPC (B = 2.035, 95% CI: 0.548 to 3.492) were significant. The indirect pathway accounted for approximately 27.55% of the total effect. The mediation model is presented in Figure 1.

Figure 1

Path analysis of the association between IPC and IC

Path analysis was conducted to examine the structural relationships between IPC and the multifactorial components of IC. The model fit indices were χ²/df = 2.47, GFI = 1.000, TLI = 0.993, RMSEA = 0.029, and SRMR = 0.011. As shown in Figure 2, shared goals and visions positively correlated with IC’s professional integration (B = 0.178) and cultural competence (B = 0.110). Internalization was negatively associated with professional integration (B = –0.230), while positively associated with technical competence (B = 0.257) and cultural competence (B = 0.234). Governance, formalization, and incentive were positively associated with both technical competence (B = 0.175, B = 0.116, B = 0.334) and cultural competence (B = 0.200, B = 0.137, B = 0.326).

Figure 2

Discussion of the results

First, the non-significant bivariate correlation contrasts with the significant indirect effect observed in the mediation model. This discrepancy likely reflects the difference between simple unadjusted associations and conditional estimates derived from multivariable analysis.

Second, our findings indicate that the mediating mechanism linking team composition and IC differs by team type. In Standard teams, the association between team composition and IC was primarily observed through IPC, suggesting that collaborative processes may constitute the principal pathway through which compositional diversity relates to IC. In contrast, IPC only partially mediated this association in advanced teams, indicating the presence of additional pathways. Although prior studies have not directly tested IPC as a mediator between team composition and IC, evidence consistently shows that multidisciplinary teams and effective collaboration are associated with higher healthcare quality and better patient experiences [27, 28]. Dai and colleagues noted that the effectiveness of team-based care depends on collaboration efficiency, irrespective of team composition [29]. Simply assembling professionals from diverse disciplines does not inherently ensure integrated care, as collaboration is inherently dynamic and complex. The differential pattern observed between advanced and standard teams suggests that greater compositional heterogeneity in advanced teams may operate through complementary mechanisms. Beyond IPC, structural features such as clearer role differentiation and more efficient task allocation may also be associated with IC [30], consistent with Bazemore et al.’s emphasis on multidisciplinary diversity in patient-centered care [31].

Finally, our study revealed a strong positive association between IPC and IC, and further path analysis identified shared goals and visions as most strongly associated with professional integration, consistent with He’s study [30]. This study also indicated that shared goals significantly influence the effectiveness of FDTs. Supper’s review identified shared goals and visions as facilitators of inter-professional teamwork in primary healthcare settings [32]. The primary purpose of teamwork is achieving team goals. Therefore, having specific, clear, and reasonable shared goals and visions may be important for enhancing team members’ motivation and forming a more collaborative professional team [33]. However, internalization was negatively correlated with professional integration. This may be associated with the current lack of effective inter-professional communication and internal conflict resolution mechanisms within Chinese family doctor contract system. Team members operate under internalized governance guidelines. However, absent such structured mechanisms, interpersonal interactions within teams may result in task boundary ambiguities, therefore undermining professional integration. Our study also found that incentive showed the strongest positive association with technical competence and cultural competence, consistent with previous studies [34]. Providing targeted spiritual and material incentives can meet care providers’ expectations and enhance intrinsic motivation for work, thereby stimulating cultural and technical competencies of the teams [30].

Implications

Firstly, promoting diversity in team composition may help improve IC and IPC, based on the observed associations. To support this, team diversity could be considered in performance evaluation systems. This may encourage teams with basic compositions to recruit practitioners with complementary expertise. Secondly, team leaders could consider strengthening inter-professional coordination frameworks, which may be associated with more effective IPC. Equitable incentive allocation linked to collaborative achievements may help align individual rewards with collective outcomes, potentially fostering partnership synergies. Finally, standardizing inter-professional communication channels and establishing team mediation protocols could help address potential barriers to professional integration related to role internalization. These measures might be supported by education programs and mediation protocols.

Limitation and further research

The limitations of this study should be acknowledged. First, the limited sample size restricted subgroup analyses based on team size and establishment year, limiting our understanding of inter-team differences. Future research could conduct subgroup analyses to explore how team characteristics affect team dynamics and outcomes. Moreover, the cross-sectional design of this study precludes causal inferences. Future studies could adopt longitudinal designs to examine the associations observed in this study and better assess potential causal relationships.