Table 1.
Brief overview of characteristics and potential differences in outcome between the QALY and DALY families of summary measures.
Fig 1.
Systematic review selection flow chart.
Fig 2.
Number of national surgical cost-effectiveness studies using the QALY or DALY metric by World Bank national income level (n = 825).
Graph shows the number of surgical cost-effectiveness QALY and DALY-based studies (y-axis) published based on work conducted in countries corresponding to the four World-Bank-defined national income levels (x-axis). Abbreviations: DALY, disability-adjusted life year; LIC, low-income country; LMIC, lower-middle-income country; UMIC, upper-middle- income country; HIC, high-income country; QALY, quality-adjusted life year
Fig 3.
Global distribution of QALY and DALY surgical cost-effectiveness studies.
Fig 3a and 3b illustrate the distribution of surgical cost-utility studies using the QALY (blue) and DALY (red) metric, respectively (n = 825). The numbers next to the colored rectangles indicate the range in the number of studies published. Fig 3c and 3d illustrate the countries for which surgical cost-utilities are most frequently reported using the QALY or DALY metric, respectively. Abbreviations: DALY, disability-adjusted life year; QALY, quality-adjusted life year
Fig 4.
Number of included QALY and DALY publications by year (n = 540).
The number of surgical cost-effectiveness publications using the QALY (light gray) has increased beginning in the 1990s. While there is some growth in the use of the DALY (dark gray), its use is not as pronounced as the use of the QALY. The drop-off in literature found for 2014 is likely due to lag in time between publication and entry into PubMed and EMBASE.