How strong are patients' preferences in choices between dialysis modalities and doses?

BACKGROUND: How dialysis patients feel about their treatment may influence how they respond to information suggesting that survival is better with a higher dose or different treatment modality. We assessed the strength of dialysis patients' preferences for their current treatment modality versus other modalities, how differences in survival between modalities and doses could influence preferences, and whether preferences differ by patient characteristics.
METHODS: We measured preference values for current health on dialysis therapy and for standardized descriptions of dialysis modalities and doses by using a sample of dialysis patients in Maryland and Massachusetts and a time trade-off technique scaled between 0 (death) and 1 (perfect health).
RESULTS: We interviewed 109 patients on hemodialysis therapy, 57 patients on continuous ambulatory peritoneal dialysis (CAPD), and 22 patients on continuous cycling peritoneal dialysis (CCPD). Hemodialysis, CAPD, and CCPD patients had similar preference values for current health (mean, 0.69, 0.74, and 0.70, respectively; P > 0.1) and lower preference values for alternative modalities (eg, mean of 0.55 assigned to CAPD by hemodialysis patients). More than 75% of patients would choose a high dose over a lower dose of dialysis if it increased length of survival by 20%, but more than 30% would not switch modality, even if it increased survival by 100%. The only characteristic associated with a difference in preference values was depression, with weaker preferences among those with mild to moderate depressive mood.
CONCLUSION: Dialysis patients have strong preferences for their current modality and are more likely to accept a higher dose of dialysis than switch modality to increase survival. Physicians should talk with patients about the modality and dose they prefer because preferences cannot be predicted by patient characteristics.