Teams of medical specialists are involved in several changes, such as technical developments, hospital mergers and the integration of doctors working part-time. Part-time working is not common in medical practices, although individual specialists stress the need for reduced working hours [1–5]. One of the problems in realising part-time work is the underlying discussion about responsibility for the continuity and quality of care. It has been argued that a minimum of hours worked is necessary in order to prevent patients and colleagues suffering from undesirable consequences, such as a lack of information or communication errors . For professionals in medical care, consultation and communication between colleagues is essential to provide high standards in quality of care . Most transfer of information is provided in social relations within informal networks at work. In this article we focus on the consequences of part-time working within those informal work-related networks. Part-time doctors with reduced working hours are limited in the amount of time they can invest in these networks in comparison to full-time workers.
Another aspect is: What type of informal work relationship is important either for part-time or full-time doctors? In work relationships of professionals, such as medical specialists, mainly three types of networks are important. Firstly, information about all kinds of work issues is transferred in communication networks. Secondly, specific professional issues are discussed in consulting networks in order to support each other. And, finally, especially in medical professions relationships of trust are important, because on the one hand confidential information about patients should be treated very carefully, and on the other hand, working in a joint partnership is based on confidential relationships with team members, which can be found in trust networks.
In addition to the type of network, the characteristics of the networks might also differ between part-time and full-time doctors. In the first place the size of informal work-related networks will be studied, because it is important to have enough network members to gain optimal benefits . Furthermore, it is important how often doctors use their network relationships and how intensive relationships are. And, finally, especially for part-time workers, it is important to build their network contacts efficiently, meaning that part-timers can be reached easily by others without the necessity to have personal contact.
In summary, we want to answer the question:
We will answer this question with regard to the work situation of medical specialists in the Netherlands.
The organisation of part-time work in self-employed partnerships
In the Netherlands most medical specialists work in self-employed teams, financially independent from hospitals. Doctors with the same specialist background select their partners for specialist teams. So they work in partnerships of independent professionals, an organisational structure in which partners are mutually dependent, and defend their own interests as well as common resources . They work as equals with the same responsibilities for quality of care, production and joint income. There is no formal hierarchical structure and all business decisions are discussed with all members of the team. This creates an organisational difficulty for the introduction of part-time work . Rationally, it is not difficult to relate the lower investments of part-time workers by pro rato income and division of tasks. However, the basic idea about sharing responsibilities and decisions within partnerships can be frustrated. Full-time workers can perceive their position as overloaded with extra work in terms of responsibilities . Part-time doctors can experience a loss of control over information and as a consequence expect a less influential position concerning core decisions within the partnership.
The independent partnerships of doctors in the Netherlands are not very formal or structured. So communication and relationships are mainly based on informal contacts and networks, which play an important role in these small teams of self-employed partners. In this article we focus on these networking relations at work, both self-organised and informal. Informal networks are mostly voluntary that is between members of the organisation who discuss issues to do with the organisation unofficially . To answer our research question we turn to complementary theoretical explanations for building social relations such as "the opportunity to meet"  and "building social capital" [12, 13]. Both approaches will be discussed below and we will point to the specific position of part-time workers. For doctors working in self-employed partnerships, working part-time is the result of negotiations with the other partners. Negotiations are focussed on the individual contribution to the total package of services the partnership has to provide for the hospital. Full-time equivalents (fte) rule the division in tasks and contributions and also the division of income. The amount of working hours is not used to define part-time working. Regardless some diversity between specialties it was found that full-time working doctors (1.0 fte, 100%) on the average work about 50 hours weekly [1, 2, 5]. Part-time partners, working 0.8 fte or 80%, will than work about 40 hours a week.
The meeting argument and part-time working
The development of social relations is basically explained by the meeting argument of Blau . People need the opportunity to meet in order to build social relations. Working together is one of the social contexts or meeting points where social relations develop . On this point part-time workers are restricted because they spend less time at work in comparison with full-timers [15, 16]. In line with this "meeting" argument, it can be expected that part-time doctors have less opportunity for daily contacts.
Another aspect related to the opportunity to meet is the size of teams. It can be expected that team size will increase with the number of part-time doctors, because a team will need more individuals to do the same amount of work. Firstly, larger teams coincide with increased opportunity to contact different colleagues, but part-time doctors are restricted in time, implying a limitation in the size of personal networks. Secondly, the frequency of contacts will decrease because of the limitation in time. The larger a team is, the lower the frequencies of contacts with each other will be . We expect that frequency of contacts is not only limited for part-timers but also for full-time doctors working in teams with part-timers.
Building social capital and part-time working
In social capital theory, building social relations and personal networks are seen as investments. Individuals enlarge their social capital by investing in others . The amount of social capital is not only based on individual efforts or investments, but also relies on the numbers of others in personal networks and the resources they can, and will, offer.
The amount of time an individual spends at work is one of the resources for building a personal network as an investment in social capital. Due to time restrictions part-timers will invest less in building social capital and consequently will have fewer resources at work . As mentioned above three types of networks are important at work: communication, consulting and trust networks.
In communication networks, we find team members who talk to each other about work on a regular basis . Since part-time doctors are less present they obviously participate less than full-timers in this kind of regular talking.
Central to the network of consulting relations are the prominent players in a team, of whom others are dependent for solving problems or getting access to technical information . Connections in this type of network provide part-time doctors with relevant information for decision-making within their partnership. Part-time workers will mainly seek instrumental support, such as advice in consulting networks. Even less strong or less frequent network relations are sufficient for receiving this kind of support [12, 13].
The network of trust gives insight into which team members would share confidential information and feedback and who gives support to someone else in crises . Trust is inevitably important within any partnership comprising a company of equals. All doctors in a partnership are dependent on the investments and support of colleagues . It can be expected that doctors working part-time and full-time do not differ in sharing confidential matters at work. Trust and sharing confidential matters is a condition of participation in a partnership. The same argument holds for social-emotional relations within a partnership. These relations imply talking about personal questions, which is related to sharing confidentiality.
Furthermore, for doctors working part-time, efficiency might be very important. In terms of social capital they might prefer to invest in colleagues who have many connections with others as this is an efficient way for part-time workers to be reached by others. Non redundant contacts offer more information that is more often new . In other words: seeking contacts among powerful or coordinating colleagues, who are in the position that they are contacted by many others, offers more information compared to the information an isolated colleague could provide us with.
Summary of hypotheses
Based on the arguments above the following hypotheses are formulated:
1. In line with the "meeting" argument, it can be expected that the size and frequency of contacts in informal work-related networks are less for part-time doctors, compared to full-timers; full-time doctors in teams with part-time workers will be limited only in frequency of contacts.
2. In terms of social capital, part-time doctors are restricted in how far they can offer and receive resources. In order to broaden their resources of information they will choose relations with colleagues who have many contacts in the team. In technical terms, part-time doctors will invest in "high reach efficiency" in informal work-related networks;
3. For building social capital it can be expected that part-time and full-time doctors do not differ in regard to the sharing of confidential matters and social- emotional relationships.
Further team and individual influences
Apart from influences in line with the theoretical background regarding the meeting argument and building social capital a few other aspects influence informal networks. Firstly, the type of specialty may influence relations in doctors' networks. In our study we included internists, surgeons and radiologists. The structure of their work environment differs, because some specialties involve many patient contacts (internists), others have restricted location tasks (surgeons in the operating room), and again others are working more with technical equipment (radiologists) and can easily leave their location. Opportunities to communicate in these specialties differ. So the type of specialty might influence the frequency of contacts and maybe the number of relationships.
Furthermore, gender seems to have a general influence on building networks at work in favour of men [21–23] and also influences related to age and tenure or years in partnership, have been found. Age seemed to be more important because being older can cause isolation [24, 25].
Informal networks at work and formal structures
Teams are not only regulated by informal contacts, but also by formal arrangements . If part-time working is introduced in a team, a possible team strategy might be to establish formal rules to support individuals in handling daily activities. It is not clear whether part-time work is related to formalisation in medical partnerships. However, some relations with the network structure can be expected. Firstly, the number of individuals in teams with part-timers will increase, because the workload has to be divided between more individuals if some are working part-time. A subsequent formal measure could be to install a formal leader, because of the increasing size of the team.