Depression in primary care and the role of evidence-based guidelines: cross-sectional data from primary care physicians in Germany

Present data indicate that PCPs see on average about 115 patients with depression per quarter, which represents about 38 patients with depression per month or 1.3 patients with depression per day. The central role in the diagnosis, treatment and care provision of PCPs has already been acknowledged numerous times [25‐27]. In Germany, outpatient mental health care of depression is mainly provided by PCPs and mental health specialists. However, present results indicate major barriers in and lack of cooperation between PCPs and mental health specialists, in particular with psychotherapists. Almost half of participating PCPs described the quality of cooperation with ambulatory specialists as medium, indicating the need for further improvement of collaborations. This finding is in line with previous research [11, 28, 29]. For example, a recent cross-sectional study on the collaboration between PCPs and psychologists reported that the vast majority of participating psychologists (64%, n = 278) found the cooperation unsatisfactory [30]. Main problem areas included poor communication and lack of time. Lack of communication and information exchange between PCPs and mental health specialists has been acknowledged numerous times in the past [31, 32], particularly with psychotherapists [33]. For example, a German study examining reply letters of specialists to PCPs found low numbers of reply letters and a need for improvement in the communication between PCPs and specialists [34]. Further, the number of specialist’s reply letters varied across specialists and was found to be lowest for, among others, psychiatrists [34]. In a recent study among PCPs, psychiatrists, and psychotherapist, participants reported a lack of structures and routines for cooperation among mental health care providers and a great need for improvement of collaboration [35]. This is in line with our findings. Furthermore, we reported that the most commonly perceived barriers to the usage of guidelines were lack of time and length of the guidelines. This finding is not surprising, given that previous studies reported similar barriers including lack of time, communication problems, and lack of established structures for collaboration. However, overall participants reported moderate satisfaction with their existing cooperation [35]. Further, the positive impact of interprofessional and collaborative care is not only reported by health professionals, but patients also report (health) benefits [32]. To sum up, interprofessional collaboration for effective primary health care has long been suggested as essential [36]. However, management of mental health disorders such as depression in primary care is complex [37] and the translation of collaborative care models into daily practice continues to be challenging [38, 39]. Interestingly, although half of PCPs (50%) reported knowing the German S3 Guideline for Unipolar Depression, the vast majority of PCPs reported never or rarely using the guideline (65%). Furthermore, as perceived barriers against the usage of the guidelines, participants reported structural problems of the care situation and barriers in communication/information exchange. These findings point towards a need for the establishment of new structures and collaboration models to increase patient-oriented outpatient care for patients with depression. To investigate optimal conditions for a successful implementation of evidence-based structures, future research should focus on interventional studies that aim at examining the effectiveness of collaborative care models between PCPs and mental health specialists as well as facilitators and barriers in their implementation. This might also include, in a first step, educational trainings for PCPs to strengthen their skills and comfort level in the management of depression and to improve the collaboration among primary care physicians [40].

Present data show that knowledge, perceived usefulness and usage of the guideline is restricted among PCPs in Germany. These findings are partially in line with previous research [6], where, similar to our results, only 41% of PCPs reported knowing the guideline recommendations for the treatment of depression. However, in contrast to our study, participating PCPs considered the guideline to be generally useful in their daily practice. Based on present findings, the central question arises, how the implementation and usage of evidence-based guidelines in primary care can be improved? Although the German Association for Primary Care was involved in the development of the German S3 Guideline for Unipolar Depression, the guideline was majorly developed by mental health specialists such as psychiatrists and psychotherapists. Drawing on present data, which show that PCPs do not know about the guideline or do not use it and do not perceive it as useful, future research should investigate effective mechanisms of guideline implementation in primary care. Further, in Germany, PCPs have on average about 7.6 min per patients [41]. This is rather low compared to other European countries such as Sweden (22.5 min), Bulgaria (20 min) or Norway (20 min) [41]. Present results suggest a lack of time as a main reason for the non-use of the German depression guideline by PCPs and past research has found that longer consultations result in better diagnosis and treatment of mental health problems such as depression [42]. Therefore, it is assumable that a lack of time negatively impacts the treatment of depression in primary care, as depression represents a health problem that requires more consultation time, especially during the first consultation [43].

As adherence to evidence-based guidelines may improve quality of care for depression [44], the present study aimed at examining factors that are related to the usage of the guideline. Results showed, that perceived usefulness of the guideline was positively associated with the usage of the guideline. These findings are partially in line with previous studies. In addition, and as reported by participating PCPs, the German S3 Guideline for Unipolar Depression is quite long and lacks practically relevant recommendations. We highly recommend designing the next guideline in a way that PCPs, who are often the first point of contact for patients with depression, perceive it as useful and relevant. To ensure the implementation of evidence-based guidelines in clinical practice, perspectives, and experiences of important stakeholders such as PCPs should be integrated in the development and dissemination of guidelines. Further, it is important to address barriers in the implementation of evidence-based guidelines in primary care [45]. Future research should further explore successful implementation strategies for newly developed guidelines, in particular for primary care. Currently, in Germany, a new national guideline for the treatment of depression is being developed. Based on present findings, we strongly recommend including PCPs perspectives in the development of the new German depression guideline. However, when examining the role of guideline-based depression care in primary care, future research should include patient-oriented health outcomes. Although the potential of evidence-based guidelines for the improvement of health care is well described, adherence to specific guidelines does not necessarily indicate best quality of care provided for an individual.

There are a number of limitations that must be outlined. First, due to the cross-sectional design we cannot draw conclusions about causal relationships. Second, although the response rate of the present study is comparable to previous primary care research [23, 46], the overall response rate was rather low. This leads to limitations in the generalizability of the sample. The present sample is based on a convenience sample as PCPs self-selected themselves into the study. Self-selection may propose a higher risk of biased data, as participants’ decision to participate may be linked with traits that affect the results of the study [47]. As participation was voluntary and most contacted PCPs did not participate in the survey, it may be that only PCPs who were specifically interested in or experienced with treatment and care of depression participated. The self-selection bias is a well-known problem in research, as self-selection has been shown to impact the validity of results [48]. Comparing present sociodemographic characteristics of participating PCPs with previous, representative PCP samples, demographic characteristics of the present sample, for example age, are comparable to some extent [49]. Further, only four of the participating PCPs reported having attended a separate training on psychotherapy, which might diminish the assumption that only PCPs who are particularly interested and skilled in mental health participated. However, a strong risk of a selection bias must be taken into account when interpreting the results, which represents a major limitation of the present study. Furthermore, aside from age groups, the present study has not assessed socio-demographic information of PCP’s patients with depression. Patients’ characteristics may influence the treatment and care provision of PCPs. In addition, the present study only focused on two geographical areas (Berlin and the surroundings) and only represents the perspectives of PCPs. Future research should aim for a more representative sample in terms of both region and population, and include perspectives of mental health specialists. For example, in order to gain a more comprehensive understanding of outpatient and primary care of depression, focus groups and interviews with all outpatient health care providers and patient representatives could be of great value.