The study explores the variation in the patient populations and describes regional differences regarding the reasons for consultations in the primary medical care in Germany. The data collection will be stratified by rural and urban areas as well as environs. The data set will include a large variety of data about physicians, patients and health care utilization.

Inappropriate supply and the increasing demand on the health care system have been of concern for health policy in Germany for the last 15 years. Concerning primary care, this especially relates to an undersupply of rural GPs (general practitioners). But there also seem to be other relevant regional differences, e.g. a lower number of house calls in larger cities, a greater number of psychiatric (co-)morbidities in the cities, a greater spectrum of services offered by rural doctors, and a difference in accessing primary and secondary care between the rural and the urban areas. Despite these results, differences between rural and urban areas have not been studied extensively in Germany. Therefore this study aims to explore regional variation of patient populations and their reasons for accessing primary care.

The study is based on standardized interviews with 240 GPs and approximately 1.200 patients in Northern Germany. Questionnaires are based on a preliminary qualitative study and were pretested. The GP's questionnaire comprises characteristics of the GP and the practice, patient types, reasons for consultation and services offered. The patient's questionnaire includes sociodemographic data and past medical history, quality of life, access to the GP, specialists and hospitals, perceived social support, health behaviour and the reasons for their consultations. Data will be analysed by descriptive statistics and different regression modelling strategies adjusted for possible confounders and the GP-induced cluster structure.

Inclusion Criteria:

• having consulted the practice within the last 3 months and
• being patient of the practice since at least 36 months (i.e. at least one consultation before 36 or more months)

Exclusion Criteria:

• no capacity to consent (e.g. because of dementia)
• insufficient German language skills to conduct interview
• not able to participate in the interviews (e.g. because of deafness or major depression)

The study is located in Northern Germany. We included all districts and cities ("Landkreise" and "Kreisfreie Städte") which have at least 20% of their area within a maximum linear distance of 100kms from our study centre in Hamburg. We assigned all districts and cities to three region types: "urban area", "environs" and "rural area". In each region type 80 GPs will be recruited and stratified by district. The prospected sample size in each district unit corresponds to its population size in relation to the total population in the respective region type. In each GP practice 15 patients will be selected at random (using random number tables) and invited to participate in the study. From our experience with similar studies we anticipate a response rate of 33%.