Note. Information on incidence and caseload was not available for Bisset [24], Csordas and Clark [30], National Pain Audit [28], and Peng et al. [17]. Divided by 12 to provide a monthly estimate since annual appointments were reported in source paper. Divided by the number of pain treatment services surveyed since the total number of appointments was reported in the source paper. Multiplied by 4.35 to provide a monthly estimate since weekly appointments were reported in source paper.