Table 2 Methodological quality scoring system
Methodological Consideration | Sources – points | Number of Sources Examined – Points | Independent Confirmation of Sources – Points | Total Minimum Points Possible | Total Maximum Points Possible |
|---|---|---|---|---|---|
Veteran Status | (Maximum Points = 20) US state bonus lists – 14 US state vital records – 18 US DMDC – 18 US VA-BIRLS – 18 US Graves Registration – 19 US Military Records (DD214) – 19 US NPRC – 20 US Special Lists – 16 Australian Service Records – 19 UK Ministry of Defense Records – 18 | 1 source – 0 2 sources – 1 3 sources – 2 | Independent confirmation – 1 | 14 | 23 |
Conflict-zone Status | (Maximum Points = 20) US state bonus lists – 17 US DMDC – 19 US Military Records (DD214) – 18 US NPRC – 19 US VA-BIRLS – 18 US special lists – 16 Australian Service Records – 20 UK Ministry of Defense Records – 18 |  |  | 17 | 20 |
Vital Status | (Maximum Points = 20) US state vital records – 20 US VA-BIRLS – 17 US SSA – 18 US VA-BIRLS & SSA – 19 US graves registration -19 US IRSb – 10 US NDI – 20 US Military Records – 19 UK Office of National Statistics – 20 UK Defense Analytic Service Agency – 19 Australian state and territorial registers – 20 Australian electoral records – 18 Australian death registers – 19 Australian immigration data – 14 Australian Army records – 19 Australian driver's license data – 17 Australian NDI – 19 | 1 source – 0 2 sources – 1 3 sources – 2 4 sources – 3 5 sources – 4 6 sources – 5 | Independent confirmation – 2 | 17 | 27 |
Cause of Death Coding | (Maximum Points = 20) US state vital records – 17 US NDI Plus – 17 Australian NDI – 17 UK Office for National Statistics – 17 Nosologist using death certificate – 18 Nosologist using death certificate plus other sources – 20 |  |  | 17 | 20 |
Study Design | (Maximum Points = 10) Proportionate Mortality – 5 Retrospective Cohort – 10 |  |  | 5 | 10 |
Total Points | 90 | 7 | 3 | 70 | 100 |