Survey response rates continue to decline across all modes of administration for public, private, and government organizations conducting survey research. This review examines response rates (RR) for direct-to-patient survey studies in health economics and outcomes research (HEOR). RR was examined for 21 HEOR patient surveys over 10 years. Patients were identified for each survey from a large, national administrative claims data base using study-specific inclusion criteria. Patients were then recruited directly by mail for participation. Surveys were administered in multiple disease areas including cardiovascular, dermatology, digestive, mental health, metabolic/endocrine, musculoskeletal, neurology, and respiratory. Survey length, incentive strategy (pre-paid vs. post-paid), incentive amount, season of administration, and condition type (chronic/acute) were assessed for impact on RR. Average response rate was 23% (SD=6). Pre-paid incentives were used in 86% of surveys. Mean RR for pre-paid incentives was 24% (SD=6) and 17% (SD=8) for post-paid incentives, supporting existing research on reciprocity garnered through use of pre-paid incentives. A $10 incentive was used in 2/3 of surveys, $20 in 4 surveys, ≥$25 in 2 surveys; surveys with larger incentive amounts were also longer surveys. RRs were somewhat higher with $10 versus ≥$20 incentives (23% [SD=6], 20% [SD=11] respectively). Season of administration was correlated with RR. Participants returned surveys administered in summer at the highest rate (RR=24%); RRs for spring administration were lowest (21%). Survey length was correlated with RR. RRs were consistently higher for shorter (8-9 page) surveys (33%) and were below average for the longest surveys (21%, ≥18 pages). Participants with chronic conditions were more likely to respond (RR=23% [SD=7] compared to 21% [SD=4] for acute conditions). Variation in RR was seen by season of survey administration, length, and incentive strategy. Incentive strategies, both type and amount, remain important considerations, as does respondent burden, with lower RRs for acute conditions and longer surveys.