Marijke Timmermans

Healthcare faces a number of challenges, such as an increasing demand, increasing patient expectations, the development and implementation of advanced technologies, and (threatening) shortages of healthcare professionals. The revision of professional roles (transfer of tasks from physicians to nonphysician clinicians) is one of the strategies to address these challenges. In recent decades, physician assistants (PAs) have been introduced on hospital wards in the Netherlands. A PA is a health professional licensed to practice medicine in defined domains, with variable degrees of professional autonomy. PAs who provide medical care for admitted patients usually work in a team comprising both PAs and MDs (i.e. residents, medical specialists). Although there is a worldwide trend of an increase of PAs in the management of hospitalized patients, evidence about the consequences of reallocating inpatient care from MDs to PAs for health care outcomes is limited. Only a few studies have compared non-acute inpatient care delivered by a PA-based team with the care delivered by a resident-based team. Overall, these studies suggested that quality of care for admitted patients delivered by a PA-based team is comparable to that of a resident-based team, and that patient evaluations are at least as good. Results of PA employment on length of stay and cost-effectiveness varied across the studies. So far all studies concerned one clinical discipline within one hospital, and thus a limited variation of patients. Given the outcomes of these studies and their limitations, we conducted a multicenter study that included PAs providing care to hospitalized patients including a range of clinical disciplines.

The central aim of this thesis was to determine the cost-effectiveness, quality and safety of hospital ward care by a PA-based team compared to a team with physicians only. Additional aims were to provide insight into the different models of medical ward care and the tasks and responsibilities of the PAs and MDs, and to identify the barriers and facilitators which care providers experience in both the initial employment of PAs for inpatient care as well as the sustainability of this employment.

Chapter 2 presents the study protocol of the main study, which aimed to determine the effects of the implementation of PAs in inpatient care on cost-effectiveness, quality and safety of care and experiences of patients. A multicenter study was designed in which the traditional model in which only MDs are employed for inpatient care (MD model) was compared with a mixed model in which besides MDs also PAs are employed (PA/MD model). Seventeen intervention wards and seventeen control wards were included across The Netherlands, from a range of medical specialties. Primary outcome measure was patients’ length of hospital stay. Secondary outcomes included indicators for quality of hospital ward care, patients’ experiences with medical ward care, patients’ health-related quality of life, and health care providers’ experiences. An economic evaluation was conducted to assess the cost implications and potential efficiency of the PA/MD model. For most measures, data was collected from medical records or questionnaires in samples of 100 patients per hospital ward. Semi-structured interviews with health care professionals were conducted to identify barriers and facilitators for the implementation of PAs in inpatient care.

Chapter 3 describes the results of a cross-sectional study with which we aimed to provide insight into different organizational models of medical ward care, and the position, tasks and responsibilities of PAs and MDs who provide medical care at wards in Dutch hospitals. Characteristics of the organizational models were collected from the heads of departments of all 34 participating hospital wards. We documented provider continuity by examination of work schedules. MDs and PAs employed for inpatient care (n = 179) were asked to complete a questionnaire to measure workload, supervision and tasks performed. We distinguished four different organizational models for ward care: 1) MS model: medical specialists provide all medical care for the admitted patients; 2) MR model: residents provide medical care for admitted patients, with supervision of medical specialists; 3) PA model: PAs provide medical care for admitted patients, with supervision of medical specialists; and 4) mixed PA/MR model: Both residents and PAs provide medical care for admitted patients, with supervision of medical specialists. The wards with PAs had the highest provider continuity. PAs spend relatively more time on direct patient care; MDs spend relatively more time on indirect patient care. PAs spend more hours on quality projects, while MDs spend more time on scientific research. Further research should focus on the impact of these differences on outcomes and efficiency of medical ward care.

Chapter 4 presents the effects of substitution of medical ward care from MDs to PAs on patients’ length of stay, quality and safety of care, and patient experiences with the provided care. To measure these effects, we conducted a multicenter matched-controlled study comparing the care on 17 hospital wards on which medical care was provided by a PA-based team, with 17 wards on which medical care was provided by MDs only. In total, 2307 patients across 34 hospital wards were included for analysis. Patients were followed from admission till one month after discharge. The primary outcome measure was patients’ length of stay. Secondary outcomes concerned eleven indicators for quality and safety of inpatient care and patients’ experiences with the provided care. This study suggests that the length of stay and quality and safety of care on wards managed by PAs is overall not different from the care on wards with traditional house staffing by MDs. Employing PAs seems to be safe and associated with better patient experiences.

Chapter 5 describes the results of the implementation of PAs on cost-effectiveness of care. This economic evaluation was performed alongside the multicenter non-randomized matched controlled study. The traditional model in which only MDs are employed for inpatient care (MD model) was compared with a mixed model in which besides MDs also PAs are employed (PA/MD model). The primary health outcome was quality-adjusted life years (QALY). The primary cost outcome included all direct health care costs from day of admission till one month after discharge. 2292 patients were followed from admission till 1 month after discharge. QALY and total costs per patient did not differ between the study arms. Regarding the costs per item, a difference of 309 euro per patient was found in favor of the MD model regarding length of stay. Personnel costs per patient for the provider who is primarily responsible for medical care at the ward, was lower on the wards in the PA/MD model. This study suggests that the cost-effectiveness on wards managed by PAs is similar to the care on wards with traditional house staffing. The implementation of PAs may reduce personnel costs, but not overall health care costs.

Chapter 6 evaluates the adherence to guidelines on medication prescribing by the PA-based teams in comparison with the teams with physicians only. To measure this, a set of 17 quality indicators has been composed by hospital pharmacists and medical specialists by means of a consensus procedure. Required data were retrospectively derived from patient medical records. 2309 patients across 34 hospital wards were included for analysis. Two of the 17 quality indicators showed significantly less non-adherence to guidelines for the PA-based teams; the indicators concerning prescribing gastric protection in case of use of NSAID in combination with corticosteroids and in case of use of NSAID in patients older than 70 years. For none of the other quality indicators for prescribing of medication a difference between the two study arms was found. In conclusion, this study suggests that the adherence to guidelines on medication prescribing on wards with the PA/MD model is not different from the adherences on wards with traditional house staffing by MDs only. Further research is needed to determine quality, efficiency and safety of prescribing behavior of PAs.

Chapter 7 presents a qualitative study on the barriers and facilitators which care providers experience in both the initial employment of PAs for inpatient care as well as the sustainability of this employment. To collect data, semi-structured interviews were held with 32 care providers across 11 different hospital wards. The recruited wards varied in medical specialty, as well as in hospital type and the organizational model for inpatient care. A framework approach was used for data analysis. Codes were sorted by the themes, bringing similar concepts together. 13 years after the introduction of PAs, there seems to be only little debate among the adopters about the added value of PAs, but organizational and financial uncertainties played an important role in the decision to employ and continue employment of PAs. Barriers to employ and continue PA employment were mostly a consequence of locally arranged restrictions by hospital management and staff physicians, as barriers regarding national laws, PA education and competencies seemed absent.

Finally, in chapter 8 the most important findings described in chapter 3 to 7 are discussed in the light of recent literature. Also the implications for clinical practice, education and future research are formulated. This thesis shows that quality and safety of care on wards managed by PAs, in a team with MDs, is overall not different from the care on wards with traditional house staffing by MDs only. Employing a PA seems to be safe and leads to a higher continuity of care and slightly better patient evaluations. The implementation of PAs may reduce personnel costs, but not overall health care costs. Organizational and financial uncertainties play an important role in the decision to employ and continue employment of PAs. Special attention should be paid to the financial embedding of PAs, as well as on the positioning of the PA within the medical team and their position in relation to other professions who could also be responsible for hospitalized patients.