Uncertainty tolerance among experts involved in drug reimbursement recommendations: Qualitative evidence from HTA committees in Canada and Poland

•Clinical evidence submitted to drug advisory committees increasingly often of insufficient quality.•Committees grapple with clinical uncertainty due to inappropriate design, comparators or end-points.•Members within advisory committees have varied tolerance for uncertainty.•Patient groups have a higher uncertainty tolerance than advisory committees.•Policy is needed to guide committees’ uncertainty management strategies and increase consistency.