OBJECTIVES: Health Technology Assessments (HTA) use clinical trial data to determine comparative efficacy and cost-effectiveness; thus study design plays a roll in market access. The objective is to determine how often reimbursement decisions cite trial design defects.   METHODS: We analyzed 1,702 HTAs from CADTH, G-BA, HAS, NICE, PBAC, and SMC. We examined the clinical assessment rationale for the decision and the reimbursement decisions. An explicit trial design defect was defined as a clinical assessment of “inappropriate comparator” or “inappropriate patient population.” Clinical assessments of lower, uncertain, or unknown efficacy or a clinical determination of insufficient or lack of evidence were defined as potential trial design defects.  RESULTS: Reviews that cited trial defects resulted in significantly more negative reimbursement decisions (6.6%) than positive reimbursement decisions (0.4%; p<.001). This pattern held true for each individual agency examined. G-BA was the agency most likely to cite an explicit trial deficit (39%), while HAS was the least likely (0.6%). In addition, significantly more reviews that cited a potential trial defect resulted in negative reimbursement decisions (44%) than positive reimbursement decisions (5.5%; p<.001). This also held true for each agency. Again, G-BA was most likely to note a potential trial defect in reviews (46%) while SMC was least likely (6.4%). Among disease conditions with more than 10 reviews, explicitly cited trial defects were mostly frequently seen in Cystic Fibrosis and Parkinson’s Disease (15% and 13%, respectively). Potential trial defects were most frequently cited in Atrial Fibrillation and Depression reviews (42% and 39% respectively).   CONCLUSIONS: Explicit and potential trial design issues have negative consequences for reimbursement outcomes. Negative decisions are more likely than positive decisions to cite trial design issues. G-BA is more inclined than other agencies to cite these trial design issues when issuing their reimbursement decisions. Manufacturers should consider market-access outcomes when designing clinical trials.