Exploring general practice research in Germany: a systematic review of dissertation topics from 1965–2023

Abstract

Background

Since its academic inception in the 1960s, Germany’s general practice has seen numerous dissertations, many of which are housed in the ‘Archive of German language General Practice’ (ADAM).

Aim

This study aims to provide the first comprehensive overview of dissertation topics from the discipline of general- and family medicine in Germany, establishing a foundation for advancing research.

Method

We employed a systematic review approach, examining 801 dissertations from both ADAM and online sources. Each topic was identified, categorized, and finalized through consensus by two independent reviewers.

Results

Our analysis encompassed 486 dissertations from ADAM, 176 from the German national library, and 139 from university libraries. A total of 167 unique research topics were identified. The predominant themes included medical education (n = 49), medication orders (n = 39), frequent consultation issues (n = 33), complementary medicine (n = 32), and screening measures (n = 29). The use of qualitative methods was constantly rising, from no qualitative methods used from 1965–1974, up to 22% of dissertations in recent years.

Conclusion

The diversity of 167 research topics underscores the vastness and complexity of general practice in Germany. This structured overview is pivotal for facilitating focused and interconnected research endeavors in the field.

Keywords:

• General practice
• dissertation
• research agenda
• historic
• archival work

Introduction

The German College of General Practitioners and Family Physicians (DEGAM) defines the discipline of General Practice as concerning ‘the provision of basic health care to all patients with physical and mental health problems in the form of emergency, acute and long-term care. It also plays an important role in the areas of prevention and rehabilitation. As the first port of call, general practitioners specialize in helping patients with all kinds of health problems’ [1].

The discipline started academically developing in the 1960s in Germany with first lectures on the topic of general practice being held at universities. In 1966 the first teaching position was established, in the same year the DEGAM was founded. Further university teaching positions and first habilitations followed in the 1970s, before the discipline became a mandatory part of the medical school curriculum in 1978 [2].

Therefore, in the earlier years of academic general practice, the focus was primarily on the education of undergraduate medical students, with clinical research projects rarely being thought about, not least because only some of the universities had their own institutes for general practice and professors, with the number growing slowly [3]. In the early 1990s, after the reunification of Germany, the German colleges of general practitioners of the East and the West merged, furthering the professionalisation of the field [4]. The five-year training to earn the specialist status for general medicine was established in 1998 and is one of the youngest specialties to be recognized in the medical education guidelines [5].

In 1993 DEGAM resolved to collect dissertations from its own discipline in a central location. Therefore, a first collection was established at the University of Marburg, Germany [6]. In 2019 this collection was moved to the ‘Archive of German language General Practice’ (ADAM) which is located at the Institute of Family Medicine of the University zu Lübeck, Germany.

This archive contains original documents and primary sources on the topic of the history of general practice in German language areas (Austria, Germany, former German Democratic Republic, and Switzerland), for example correspondence of pioneers of the field. Additionally, ADAM also collects medical dissertations and habilitations [7]. Every year, the institutes and facilities of general practice are asked to submit completed dissertations into the archive with the aim to digitalise the works and make them available for future research.

In Germany two different academic grades can be reached: the promotion and the habilitation. The specific requirements are given by the individual University. Promotion refers to the conferral of a doctorate and the term dissertation is used for the doctoral thesis written about a piece of research that was produced to gain the title of ‘Dr. med.’. In Germany to aim at this title is voluntary for physicians, about 60% choose to complete it. The other 40% are doctors by profession but not allowed to carry the title Dr. med. before their names. A dissertation does not necessarily go along with a publication. The exact percentage of how many dissertations go along with a publication in general practice, is unknown. However, generally about half of the candidates do publish their research [8]. The promotion process can be started part time while still studying medicine and takes on average about three to five years. The requirements for a promotion are therefore generally rather lesser than those of a PhD.

A habilitation is the verification of the qualification to teach and to research a specific discipline independently. It can be accomplished after the promotion and takes about a further six years. The requirements are usually higher than those of a PhD, e.g. including eight to 15 publications. The title gained after a successful habilitation is ‘Privatdozent’ which is comparable with ‘assistant professor’ [9].

So far, no overview of the topics of dissertations within general practice in Germany is available. This analysis aims to create such an overview. Furthermore, using the example of home visits, we aim to check, to what degree researchers are aware of each other’s works.

Methods

We identified dissertations stored in ADAM and available through online resources and screened them, oriented on the modalities of a systematic review. Additional online resources we used were the German National Library (DNB) and the publication servers of all German universities with institutes or facilities of general practice.

To get an idea about the percentage of total dissertations present in the archive, we screened through the web presences of all institutes and facilities of general practice regarding information about finished dissertation projects.

Search terms used in the online catalogues of the universities’ libraries and publication servers as well as the DNB were: ‘Allgemeinmedizin, Hausarzt, Institut für Allgemeinmedizin, Abteilung für Allgemeinmedizin’ (general practice, primary care physician, institute for general practice/family medicine, department for general practice/family medicine) and we included works up to March 1^st, 2023.

After we removed duplicates, dissertations that were not available in full text were excluded from further analysis as well. We assessed the availability by searching for the full text dissertation we identified in the catalogue of the university’s library the dissertation was written at, and additionally the DNB. Not available was defined as: works that only exist in a printed version in a specific university’s library or if there was information about a dissertations existence without specifying where it could be found. Further reasons for exclusion were: language other than German or English, origin not from a university in Germany, topic not related to general practice, and dissertations origin not from a general practice institute/supervisor.

Remaining dissertations were looked at one by one, tagging each with an index term. Index terms were not defined before the analysis but found deductively, orientated on the method of content analysis by Mayring [10]. Each researcher independently analysed the abstracts of the dissertations and categorized them. In a second step categories were discussed, and a consensus index term was found. In cases where a dissertation could be categorised by more than one possible index term, the authors discussed and focused on the main point of the dissertation. Additional information that was obtained about every dissertation was: the name of the author, the title, the year, the institution it was written at, the availability and a short summary of the content and methods with a space for additional commentary.

We chose the topic of home visits after a discussion among the authors, as it represents a typical task for GPs in Germany and is still a current research topic [11].

Results

When combining all the search strategies and exclusions mentioned above (Figure 1), we identified 801 dissertations. They were written between 1965 and March 2023. Of the dissertations, 486 were already available in ADAM and an additional 176 could be found in full text in the catalogue of the DNB. The publication servers of the universities provided a further 139 dissertations.

Figure 1. Prisma-Flowchart [15].

On the universities’ websites, in some cases, extensive information could be found, even from a time before dissertations were preserved digitally. The information was often provided in the form of lists of finished or ongoing dissertation projects. Some lists were up to date while others had not been updated in years. In other cases, information only went back a few years or was missing completely. In those instances, sometimes the online catalogues of the university libraries could provide additional information but even those could sometimes miss information about older works. Additionally, any search in online catalogues was limited by the use of specific search terms.

When looking at the time in which the dissertations were written, we observed that the biggest margin of the works available for analysis were written after 2015 (n = 210), followed by the years between 1985 and 1994 (n = 178) and 2005 to 2014 (n = 158). Overall, 473 (59%) of the works were stored in print, while 328 (41%) were stored digitally. In the years leading up to 2004 most of the works were available on paper, the rise of dissertations being available digitally could be observed from 2005 onwards. (Table 1)

Topics of the dissertations spanned a wide range, with 167 different research topics identified via index terms. The twenty index terms that came up the most can be seen in Figure 2. These covered n = 383 (48%) of all dissertations included. The methods of the different dissertations are varied, we found quantitative and qualitative studies, mixed-methods and cross-sectional studies, practice-based and epidemiological research as well as (systematic) reviews.

Figure 2. Index terms.

Table 1. Overview of results.

Years	Number of dissertations	Qualitative methods	Quantitative methods	Other methods*	Available online	Female researchers
1965–1974	13	0%	100%	0%	0%	23%
1975–1984	116	18%	75%	7%	0%	25%
1985–1994	178	14%	74%	12%	0%	47%
1995–2004	126	12%	77%	11%	15%	53%
2005–2014	158	15%	75%	10%	79%	66%
2015–2023	210	22%	53%	25%	88%	71%

*Other methods include: Systematic Reviews, Mixed Methods, Discourse Analysis, Routine Care Data Analysis.

In the years between 1965 and 1974, the index terms that came up the most, were ‘out of hour care’ (n = 4), ‘frequent consultation issues’ (n = 3) and ‘patient collectives’ (n = 2). Between 1975 and 1984 it was ‘medication orders’ (n = 10), ‘frequent consultation issues’ (n = 8) and ‘patient collectives’ (n = 7). In the following years between 1985 and 1994 the three most used index terms were: ‘complementary medicine’ (n = 12), ‘education’ (n = 7) and ‘hypertension’ (n = 6). Between 1995 and 2004 it was ‘screening measures’ (n = 8), ‘education’ (n = 6), ‘medication orders’ (n = 6) and ‘diabetes’ (n = 6). In the years between 2005 and 2014 the most used terms were: ‘education’ (n = 18) and psychosomatic primary health care’ (n = 10). In recent years after 2015, ‘education’ (n = 27) was the most used index term, followed by ‘medication orders’ (n = 10) and ‘interdisciplinary cooperation’ (n = 9).

Regarding the exemplary topic of home visits, we identified nine dissertations. The index term first came up in 1972. It was used twice between 1975 and 1984 and then twice again between 1985 and 1994. It came up once in 1998, then not again until 2011 before it returned to focus after 2015. The first two dissertations were both written in Munich and the second one, written six years later is citing the first one multiple times. The third work was written at a different department in 1982 and analysed a program of the University of Hannover in which students accompanied doctors doing home visits. The author cited the first dissertation mentioned but did not cite the second one. This continued for later dissertations from the with each author being aware of one, or in some cases two, of the other dissertations written on the topic with none being aware of all of them. An exception was a one that was written in 1987 in the former GDR which cited none of the other dissertations. After the dissertation written in 1989 there was a gap and the most recent three dissertations were written in 2011, 2017 and 2019. The work from 2011 did not refer back to any older dissertations while the other two were aware of the research done in 2011, citing the same published article from the dissertation. Six of the dissertations were available on paper in the archive, while three were available digitally. The first two dissertations were both written at the same university while all the others originated from different institutes or facilities. Each author illuminated a different aspect of the topic. Two works concentrated on home visits to nursing homes specifically, while the other seven addressed visits to a single patient home or matters of home visits in general. The newest three works used the method of qualitative analysis, as did the work from 1982. All the dissertations used quantitative methods, except for one, which analyzed the equipment that doctors travelled around with on home visits and compared it to the literature recommendations for doctor’s kits.

Discussion

Summary

In the context of Germany’s general practice research evolution since the 1960s, our systematic review of 801 dissertations spanning from 1965 to March 2023, uncovered 167 distinct topics. This collection showcases the trajectory of the discipline and provides a deeper understanding of its thematic focus over the decades. By assessing the index terms alongside the dissertation dates, we can discern a timeline for certain topics, as illustrated by our exploration of home visits. A noteworthy observation from our analysis is the ease of referencing in the digital age compared to the challenges presented by older, paper-based dissertations.

Strengths and limitations

This is the first analysis of the topics of dissertations within general practice in Germany. As a limitation, the question arises weather all dissertations that have been finished could be found through the search methods described above. We found that the online presences of university departments can be an insufficient source of information on current and finished dissertations. When looking at the works present on paper in ADAM it can be found that a lot of them were written between 1985–1994. A possible explanation for this might be that the archive includes the collection from Marburg that was started in 1993 [5]. A lot of those works are presumed to be from that initial call. In the first years of the collection there was a regular influx of new dissertations that started to subside in later years. After it became more customary to provide digital copies of dissertations the number of paper-based works began to decline. In this process of transition, it could be possible that some works from that time cannot be found easily. When looking at the individual dissertations about home visits we cannot rule out that older dissertations were not cited because they were thought to be outdated.

Comparison with existing literature

When comparing our findings concerning the topics most researched to previous data about the subject, they can be compared to an analysis of research output between 2000 and 2010 [12]. This research focused primarily on the types and numbers of studies and publications; they identified cross sectional studies as the most frequent types of studies. When looking at range of topics, medical education was the topic most identified in our results, also being the topic of most cross-sectional studies between 2000 and 2010. Clinical topics coming up the most were psychological complaints, cardiovascular- and musculoskeletal diseases. Similar topics are covered by our index terms ‘psychosomatic primary health care’, ‘hypertension’, ‘stroke’ and ‘back pain’ which all range among the twenty most often used index terms.

Generally, upper respiratory infections and hypertension are the most common reasons for consultations in general practice in age groups of 25–44- and 45–65-year-olds respectively [13]. In our research, ‘Hypertension’ as an index term came up 22 times, while ‘respiratory infection’ was used four times. However, there were several dissertations focused on prescribing antibiotics in such infections that were grouped under the index term of ‘medication orders’.

Other frequent consultation issues that came up in our research as well as the epidemiological tables include ‘diabetes mellitus’ which was an index term we used 22 times and a consultation issue that ranked among the top ten in all ages above 45 and ‘back pain’, used 10 times, which is one of the most frequent consultation issues in general practice among over 45-year-olds. ‘Frequent consultation issues’ as an umbrella term is an index term, we used 33 times. It mostly was used to create an overview concerning specific regions, time periods or looking at a specific practice’s patients.

When comparing the gender distribution of completed dissertation projects with a study carried out in Swedish Family Medicine where especially in the years between 2011–2020 more women than man achieved PhDs, this effect can be seen in our research as well [14]. While in the time between 1965–1984 more men than women completed dissertations in the field of general practice, the ratio evened out in the time from 1985–2005. From 2005 on women completed a higher percentage of dissertations, in the years after 2015, they wrote 71% of doctoral theses included in our research. (Table 1)

Implications for research

The diversity of possible research topics in relation to general practice can be mapped onto the topics of the present dissertations. A structured overview of dissertation topics in the field of general practice is an important foundation for efficient research that can build up on one another. Authors are not always aware of the dissertations predating their own, especially if the dissertations are older and not available online. It is a concern, that if researchers are not aware of other studies, there is a danger, that we address the same research question over again instead of moving forward.

To prevent the research done by doctoral candidates in the field of general practice going unnoticed, it is important to make it available to the scientific community, not only by publishing results in easily accessible formats but also by making dissertations available online. For that purpose, within ADAM, we are building a database of German language dissertations to make them available for research.

Abbreviations
DEGAM	=	German College of General Practitioners and Family Physicians
ADAM	=	Archive of German language General Practice
DNB	=	German National Library
GDR	=	German Democratic Republic (former East Germany)

Disclosure statement

Authors declare that they do not have any conflict of interest.