The present study analyzed the use of ambulatory healthcare services by multimorbid patients in primary care settings. Within the framework of Andersen Behavioral Model of Health Services Use, it explored the individual, contextual, and societal factors for four outcomes: the use of homecare services, the use of other allied health services, the numbers of GP–patient contacts and the number of specialists involved. The factors associated with these four outcomes differed (e.g., use of other allied health services were associated with pain, whereas the number of GP–patient contacts was essentially associated with factors pertaining to medical severity), and only the age factor was associated with all of them. Interestingly, only 15% of the sample’s patients used homecare services, and although the number of specialists consulted increased with age up to 70 years old, surprisingly, it decreased after that. Andersen’s model revealed that need factors were associated with all four outcomes, predisposing factors with three (homecare, GP–patient contacts, and specialist consulted), and enabling factors with only two (homecare and specialists consulted). This shows that the use of ambulatory healthcare services depended, logically, on objective medical needs, but also on contextual or individual factors.
As expected, multimorbid patients used more homecare services than the general population (7) (35), and greater age was significantly associated with higher use (36). Despite a lack of social support usually being considered a predictor of healthcare services use (37), the present study found that social support seemed instead to be a promoter of its use. Indeed, patients with an informal caregiver or who were less socially deprived were more likely to use homecare services. These results are in line with those of a Canadian study by Lai L. et al. on Chinese immigrants (38).
Reporting pain or discomfort was the only factor associated with the use of other allied health services, which was the only outcome solely associated with need factors. This suggests that the use of other allied health services may be influenced solely by necessity. We found no previous study that specifically analyzed the use of other allied health services by multimorbid patients. Bähler et al. studied the costs linked using other allied health services, laboratory tests, and medical devices (“other outpatient costs”), whereas Heins et al. recorded that 46% of multimorbid patients without cancer used physical therapy and 7% used occupational therapy, which was in line with the present results (39).
Multimorbid patients in the present study frequently consulted their GPs: this increased with age and the number and severity of their chronic conditions—a result in line with other European studies (40, 41). However, Schellhorn et al. found that age did not play a significant role in predicting the frequency of visits to physicians by older Swiss adults (42). GPs’ evaluations of need factors with regard to the number of GP–patient contacts showed an associations with the health status and the clinical severity of multimorbidity, confirming the results of previous studies (16, 43-45).
Interestingly, the present study revealed that although the number of specialists consulted initially increased with age, it decreased after 70 years old, in contrast to other studies (12, 46). We could hypothesize that even though the oldest patients have increasing numbers of chronic conditions, they may have more difficulty attending specialist consultations or may set different priorities. Restriction of access and discrimination are other factors potentially influencing the number of specialists consulted. Furthermore, the decreasing number of specialists consulted at older ages may be compensated by increasing contacts with GPs. This could suggest that their care tends towards a more holistic focus on the patients whole-person rather than on their specific diseases: Close GP–patient relationships and the continuity of care prevent the overuse of specialist consultations (47). Higher educational level has been described previously as a predictor of higher number of specialist consultations (46).
Our study found no association between healthcare service use and disease or treatment burden, which might have been thought of as obvious predictors of use. The concept of treatment burden is recent and there are only few publications on this topic with none describes the specific relationship between treatment burden and healthcare services uses. (48, 49)
The number of medications used was positively associated with three outcomes (homecare services, GP–patient contacts, and specialists consulted). Unsurprisingly, the number of medications used increased with the number of chronic conditions (8, 16, 44, 50).
As described above, Andersen’s model enabled us to analyze and classify individual, societal, and contextual characteristics according to the three categories of factors of ambulatory healthcare use: predisposing factors, enabling factors, and need factors. This model was initially designed as a tool to analyze inequalities in healthcare services use (17, 30, 31). In the present study, predisposing and need factors contributed most to explain ambulatory healthcare services use. However, each ambulatory healthcare use outcome was associated with a different combination of factors, illustrating the complexity of caring for multimorbid patients where all three factors of the Andersen model can influence patient’s health care services use. We suggest that this indicates the importance for GPs to develop more patient-centered care rather than disease-oriented care as proposed by most guidelines. Indeed, May propose to start with “treatments for patients and not for diseases”. (51) This is in line with other authors’ suggestions of giving less importance to disease-centered care and starting to care for patients holistically. (52, 53) In reality, demographic and socioeconomic status or individual perceived health may have more influences on the health care service use than a given chronic condition. As multimorbity grows with aging populations, caregivers and political decision-makers should be aware of the need to integrate all three factors from the Anderson model into planning health care access and thus reducing inequalities. Future research about the health care service use for multimorbid patients in primary care should integrate variables and the reflection of the Andersen model.