Recruiting a representative sample in adherence research-The MALT multisite prospective cohort study experience.

Medication adherence is an important determinant of transplant outcomes. Attempts to investigate adherence are frequently undermined by selection bias: It is very hard to recruit and retain non-adherent patients in research efforts. This manuscript presents recruitment strategies and results from the MALT (Medication Adherence in children who had a Liver Transplant) multisite prospective cohort study. MALT sites recruited 400 pediatric liver transplant patients who agreed to be followed for 2 years. The primary purpose was to determine whether a marker of adherence, the Medication Level Variability Index (MLVI), predicts rejection outcomes. The present manuscript describes methods used in MALT to ensure that a representative sample was recruited, and presents detailed recruitment results. MALT sites were able to recruit a nationally representative sample, as determined by a comparison between the MALT cohort and a national sample of transplant recipients. Strategies that helped ensure that the sample was representative included monitoring of the outcome measure in comparison with a national sample, drastically limiting patient burden, and specific recruitment methods. We discuss the importance of a representative sample in adherence research and recommend that future efforts to study adherence pay special attention to sample characteristics.

Long-term patient outcome and quality of life after liver transplantation: analysis of 20-year survivors.

OBJECTIVE: To evaluate patient survival and allograft function and health-related quality of life (HRQOL) 20 years after orthotopic liver transplantation (LT). SUMMARY OF BACKGROUND DATA: Although LT is the established treatment of choice for acute and chronic liver failure, allograft function and recipient HRQOL 20 years after LT remain undefined. METHODS: We performed a prospective, cross-sectional study of LT recipients surviving 20 years or more. Clinical data were reviewed to identify factors associated with 20-year survival. Survivors were directly contacted and offered a survey to assess HRQOL (SF-36; Liver Disease Quality of Life), social support, and cognition (Neuropsychological Impairment Scale). Logistic regression analysis was performed to identify clinical factors influencing HRQOL 20 years after LT. RESULTS: Between February 1, 1984 and December 31, 1988, a total of 293 patients (179 adults, 114 children) received 348 LTs. Of the 293 patients, 168 (56%) survived for 20 years or more. Actuarial 20-year survival was 52% (patient) and 42% (graft). Factors associated with 20-year survival included recipient age <18 (P = 0.01), nonurgent LT (P = 0.01), no retransplantation (0.02), female gender (0.03), absence of biliary complications (P = 0.04), and short total ischemia time (P = 0.05). Rejection episodes were seen in a greater proportion of 20-year survivors than in nonsurvivors (35% vs. 27%; P = 0.3). Of the 168 survivors, 87 were contacted, and 68 (78%) completed the HRQOL surveys. Compared with the general population, survivors had lower physical scores (P < 0.01) but comparable mental scores on the SF-36. Overall HRQOL was significantly better in 20-year survivors than in patients with chronic liver disease, congestive heart failure, or diabetes. Clinical factors associated with improved post-LT HRQOL were younger age at LT, allograft longevity, and strong social support. More than 90% of pediatric survivors completed high school. After LT, 34% of pediatric recipients married, and 79% remained married at 20 years' follow-up. CONCLUSIONS: More than 50% of LT recipients survive 20 years, achieve important socioeconomic milestones, and report quality of life superior to patients with liver disease or other chronic conditions. LT is a durable surgery that restores both long-term physiologic and psychologic well-being in patients with end-stage liver disease.