Facilitating and understanding the family's choice of injection device for growth hormone therapy by using conjoint analysis.

BACKGROUND Conjoint analysis involves the measurement of consumer preferences between choice alternatives. AIMS AND OBJECTIVES To investigate the use of conjoint analysis in facilitating and understanding choice of growth hormone injection devices. METHOD AND SUBJECTS 56 patients and their parents participated in an electronic, computer-based interview. The interview took a median time of 18 min (range 12-30) and allowed an immediate matching of injection devices to the family's preferences. RESULTS Amongst the key drivers of choice, lack of bruising was rated highest and designated an index of 100. Compared to this, the remaining attributes in order of desirability were: auto-injector (98), lack of pain (93), lightweight (88), silent (82), ready-mixed (77), ease of holding (69), telephone helpline (66), needle-free (62), small size (60), nurse support (47), hidden needle (45), stored in fridge (13) and home delivery (6). Out of the 17 families who had already chosen a device previously by discussion with the clinic nurse, the computer model placed their device either as first or second out of seven devices tested. CONCLUSION Adaptive or interactive conjoint analysis applied at the patient level can facilitate the choice-making process whilst providing an insight into the relative importance of the key features that influence choice.