In addition to our previous research, we tried to identify further reasons for a lack of agreement between the understanding of illnesses in GPs and their patients. The focus groups with multimorbid patients and their GPs yielded seven themes of reasons for disagreement regarding illnesses between patients and their GPs . These themes concern the need to enhance the communication and cooperation between health care professionals, to improve the communication between GP and patient, and to increase the patients' disease knowledge.
Enhancing the Communication and Cooperation Between Health Care Professionals
There are several challenges in the management of chronic diseases, especially multimorbidity. In our study, GPs and patients often reported interface problems between professionals and a lack of interdisciplinary communication. This is in line with the findings of other studies. Fried et al. identified barriers in clinicians' preferred approaches to decision making in focus groups with physicians, nurse practitioners and physician assistants. One barrier was the interaction with specialists. Smith et al. reported inter-professional communication difficulties as well. A study from Gill et al. emphasized the uncoordinated health services from the patients' points of view. Patients were frustrated over poor communication and a lack of care coordination. Moßhammer et al. assessed relevant deficiencies in, and barriers to, the cooperation between general practitioners and occupational health physicians in Germany. They identified problems areas such as a lack of communication, insufficient cooperation and a lack of knowledge, prejudices, competition and mistrust between the two groups. These studies showed that there is a great need for optimizing interface problems and interdisciplinary communication.
These problems could be handled by strengthening the role of the GP as a coordinator in the German health care system. This possibility has already been installed in a special GP-centred, health care contract ("Hausarztzentrierte Versorgung", HZV), which the German statutory health care funds are legally required to offer. The evaluation of these contracts by Klingenberg et al. found that 24.9 % of the surveyed GPs reported an improvement concerning the cooperation with specialists. The HZV might, therefore, be a promising approach to improve interface problems and the lack of interdisciplinary communication. Nevertheless, there is a need for optimizing the reporting system in ambulatory care in Germany. The specialists' obligation to submit a report to the GP should, therefore, be analyzed by independent studies and monitored by the National Association of Statutory Health Insurance Physicians in Germany.
Improving the Communication Between GP and Patient
A predominant problem, concerning the communication between doctors and patients, was the insufficient consultation time, which was also described in other studies. In an international comparison, the median patient contact time was the lowest for German primary care practices with 9.1 min compared to a median ranging from 10.3 (Italy) to 28.8 (Sweden) minutes in the other countries. Especially German patients with many chronic conditions might have too little time with their doctors to talk about their diseases and their treatment plan.
In our study we also identified different factors complicating communication, e.g. if patients were functionally impaired. Luijks et al. reported mental health problems as a major barrier negatively influencing the management of multimorbidity. The synthesis of Sinnott et al. summarized cognitive impairment, poor social supports and finances, and a low level of motivation as factors influencing patients' ability to understand and adhere to treatment. On the other hand, a good, personal patient-doctor relationship positively influenced the communication and the management of multimorbidity.
Another challenge for the communication between GP and patient was the different prioritization of diseases. Our results suggested that GPs more often prioritized diseases that affect the prognosis, while patients more often prioritized diseases with impairments. In concordance with our results, Smith et al. described different goals of clinicians and their patients. Another qualitative study from our MultiCare study group, by Löffler et al., focused on the dealing with multimorbidity. They conducted separate narrative interviews with GPs and their patients and found that patients and GPs had different priorities: GPs focused on the management of life-threatening diseases, while patients prioritized autonomy and social life. A quantitative study by Zulman et al. demonstrated patient-provider concordance. Patients and providers where asked to rank their most important health concerns. Patients prioritized symptomatic conditions such as pain, depression or breathing problems more than their providers. Other studies also showed differences between older patients and their general practitioners regarding prioritization.
To improve the communication between GP and patient regarding the management of multiple diseases, a common prioritization of the treatment goals could be useful. For example, this could be achieved by a narrative doctor-patient dialogue, which is currently being tested in a cluster-randomized controlled trial in Germany.
Increasing the Patients' Disease Knowledge
Our focus groups pointed out that the patients' diseases concepts were different from the doctors' medical concepts. For example, patients did not distinguish between similar diseases e.g. rheumatoid arthritis and joint arthrosis. Or they had no understanding for the chronicity of an illness. This different understanding of diseases could cause misunderstandings that complicate the treatment, especially in multimorbidity.
Kivelä et al. demonstrated, in a systematic review, that health coaching had positive effects on patients' physiological, behavioural and psychological conditions. Therefore, patient education could improve patients' disease knowledge and, thus, the compliance regarding the management of multiple chronic conditions. GPs should motivate their patients to participate in existing education programs for patients e.g. diabetes education. Certainly, these education programs are limited in the statutory health insurance system in Germany. For this reason, the GPs role of explaining the diseases to their patients remains a great part of their work. In the development of clinical practice guidelines for multimorbid patients, the topic "patient education" should also be taken into account.
Strengths and Weaknesses
To our knowledge, this is the first study analysing reasons for disagreement regarding illnesses between patients and their GPs by performing focus groups with GPs and, in particular, with their multimorbid, older patients in Germany. We took into account both the providers' and the consumers' perspectives. The qualitative approach added further reasons for a lack of agreement between the GP and his/her patient to our previous study.
However, we might have missed some reasons for disagreement between GPs and patients because of the setting of the study. Our recruitment took place solely in a large German city, so that rural areas were not included in our study. Furthermore, our results are only based on multimorbid patients and their GPs in Germany. The problem areas identified in our study might also vary from results of studies in other countries, because of different health care systems.