Table 3.
Description of data sources used for ascertaining vaccination status in severe acute respiratory infections case-patients identified, pilot case–control study for influenza vaccine effectiveness in Central-America, 2012 (n = 1,186)
| Costa-Rica (n = 647) | El Salvador (n = 334) | Honduras (n = 107) | Panama (n = 98) | |||||
|---|---|---|---|---|---|---|---|---|
| Data source | 6 months − 11 years with chronic conditions, n = 339 (%) | ≥65 years, n = 308 (%) | 6 − 59 months, n = 287 (%) | ≥60 years, n = 47 (%) | 6 − 35 months, n = 60 (%) | ≥60 years, n = 47 (%) | 6 − 59 months, n = 91 (%) | ≥60 years, n = 7 (%) |
| Surveillance forms or databasea | 184 (54)a | 39 (13)a | 20 (7) | 7 (15) | 13 (22)a | 13 (28)a | 17 (19)a | 0 (0) |
| Vaccination cards | 184 (54) | 39 (13) | 60 (21) | 0 (0) | 44 (73) | 17 (36) | 17 (19) | 0 (0) |
| Nominal vaccination registers | 150 (44) | 262 (87) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 19 (21) | 0 (0) |
| Local EPI records or vaccination facilities records | – b | – b | 29 (0) | 2 (4) | 2 (3) | 17 (36) | 0 (0) | 0 (0) |
| Verbal report of vaccination card review (over the phone) | 5 (2) | – b | 0 (0) | 0 (0) | 13 (22) | 13 (28) | 0 (0) | 5 (71) |
| Medical records | 0 (0) | – b | 15 (5) | 8 (17) | 0 (0) | 0 (0) | 52 (57) | 0 (0) |
| Unspecified document reviewedc | 0 (0) | 0 (0) | 110 (38) | 25 (53) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| Unreachable patient/undocumented | 0 (0) | 7 (0) | 53 (18) | 5 (11) | 1 (2) | 0 (0) | 3 (3) | 2 (29) |
aSurveillance forms information was based on the review of vaccination cards in Costa-Rica and Panama, and on over-the-phone readings of vaccination cards in Honduras
bData source not used
cMay include vaccination card or any other paper document