Prognosis, proof and priorities in dietetic practice

Abstract

The Dutch prevention policy document 2004-2007 expresses the need for more disease prevention interventions in the curative domain of health care. In hospitals the dietician is traditionally involved in preventive activities. The recent focus on prevention provides an opportunity to reflect on what facts and principles should guide priorities in hospital-based dietetic practices. This thesis consists of a collection of studies addressing patient selection based on future risks (prognosis), selection of interventions based on evidence for effectiveness (proof) and principles for priority setting based on a critical appraisal of the available scientific data and guidance of ethical values (priorities). The central question in this thesis is: What information, knowledge and values are needed to guarantee the quality of priority decisions in a hospital-based dietetic department? Chapter two presents two studies on undernutrition due to the gastrointestinal side-effects of intensive chemotherapy and total body irradiation in oncohaematological patients. The results may help dieticians to improve selection of patients who benefit either from parenteral nutrition support during admission (chapter 2.1) or from a more intensive counselling program during the recovery phase post-transplant (chapter 2.2) in order to prevent in-hospital complications as well as loss of (quality of) life time. The two studies in chapter three add to our knowledge on the effect sizes of specific dietary and lifestyle changes to prevent premature death in patients with coronary artery disease. The results show that effect sizes of dietary and lifestyle changes are relevant and comparable to the effects of routine prophylactic pharmacological treatments. Chapter four concerns patient selection policies of dietetic departments. Priority decisions should be guided by reflection on ethical values such as beneficence, autonomous choice and distributive justice and be based on the best available evidence. Professional accountability may be facilitated by explicit choices, transparent policy documents and openness for feedback. Exploring the implications, it is stated that at least three societal factors in western societies should be weighed in the priorities of hospital-based dieticians: the large burden of cardiovascular diseases, the substantial health disparities between socio-economic groups and the increasing frequency of unhealthy dietary behaviours. We conclude that priority decisions should be based on reliable information on the (future) needs of all relevant patient groups, knowledge about evidence-based benefits of dietary interventions and a clear vision on relevant ethical values. For those making the priority decisions, competencies related to appraisal of scientific data, ethical deliberation, coping with social diversity and quality management are essential