INTEGRATING QUANTITATIVE PREFERENCE-RELATED EVIDENCE INTO HEALTH TECHNOLOGY ASSESSMENT: THE CASE OF VENTILATION FOR CHRONIC OBSTRUCTIVE PULMONARY DISEASE

Purpose: Recently, there has been increased effort to formally consider patient values and preferences in health technology assessment (HTA). Incorporating systematic reviews on patient preferences is one way of achieving this goal. To explore the feasibility of such an approach, we conducted a systematic review of patient preferences for ventilation among patients with chronic obstructive pulmonary disease (COPD).

Method: We searched MEDLINE, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Collaboration, American Economic Association’s electronic bibliography, EMBASE, Health Economic Evaluations, and PsycINFO databases for preference-relevant human studies published in English from 1990 through November, 2010. Selection criteria for the studies were: (i) study participants met criteria for COPD; (ii) at least one of the study interventions included invasive and/or non-invasive ventilation for the treatment of COPD; (iii) patient preferences were reported; and (iv) the study was not qualitative. Studies were selected based on title and abstract. Two authors independently extracted data using a standardized extraction table. Disagreement was resolved by discussion or consensus with a third party.

Result: Among 1833 identified citations, 12 studies were eligible for inclusion. 11/12 studies interviewed patients once; most studies elicited a stated preference for one or more types of ventilation.  58-77% of COPD patients indicated that they would try mechanical ventilation (MV). Studies that asked COPD patients about indefinite MV found that 60-78% would reject the intervention. Two studies that provided more information to patients by giving them in-depth decision aids found that only a minority were willing to accept MV.   Preferences for MV were not consistently associated with age, gender, pulmonary function, the presence of co-morbid conditions, or current quality of life.  However, most COPD patients would forgo MV in the event that they were seriously incapacitated, such as being bedbound, or suffering from dementia.

Conclusion: Searching for and abstracting data from studies of patient preferences is feasible, and offers substantial insights beyond conventional evidence reviews and cost effectiveness analysis in HTAs. However, the process is difficult because of the heterogeneity of study designs, outcome measures, and terminology. Further development is required before preference reviews can become a routine part of HTA.