Table 1.
Characteristics of Participants, 5-State Influenza Mortality Investigation (Alaska, Arizona, New Mexico, Oklahoma, Wyoming), 2009
| Characteristic | Level | Cases (n = 145) |
Controls (n = 236) |
|
|---|---|---|---|---|
| Sex | Female | 73 (50%) | 120 (54%)a | |
| Male | 72 (50%) | 104 (46%) | ||
|
| ||||
| Age Group | < 5 years | 9 (6%) | 32 (14%) | |
| 5–10 years | 4 (3%) | 33 (14%) | ||
| 11–20 years | 14 (10%) | 52 (22%) | ||
| 21–30 years | 19 (13%) | 50 (21%) | ||
| 31–40 years | 9 (6%) | 23 (10%) | ||
| 41–50 years | 23 (16%) | 21 (9%) | ||
| 51–60 years | 35 (24%) | 17 (7%) | ||
| 61–70 years | 14 (10%) | 5 (2%) | ||
| 70+ years | 18 (12%) | 3 (1%) | ||
|
| ||||
| State | Alaska | 11 (8%) | 22 (9%) | |
| Arizona | 47 (32%) | 49 (21%) | ||
| Oklahoma | 37 (26%) | 74 (31%) | ||
| New Mexico | 47 (32%) | 85 (36%) | ||
| Wyoming | 3 (2%) | 6 (3%) | ||
|
| ||||
| Residence Typeb | Urban | 3 (4%) | 19 (9%) | |
| Large Rural | 17 (19%) | 81 (38%) | ||
| Small Rural | 8 (9%) | 16 (8%) | ||
| Isolated | 60 (68%) | 94 (45%) | ||
|
| ||||
| Race (when asked for a single race) | AI/AN | 25 (17%) | 27 (11%) | |
| White | 110 (76%) | 169 (72%) | ||
| Asian | 0 (0%) | 14 (6%) | ||
| Black | 5 (4%) | 3 (1%) | ||
| Other | 3 (2%) | 23 (10%)c | ||
| Unknown | 2 (1%) | 0 (0%) | ||
|
| ||||
| AI/AN race (alone or in combination) | 32 (22%) | 38 (16%) | ||
|
| ||||
| Specimen Collection Date | Summer (May – Aug) | 17 (12%) | 27 (11%) | |
| Fall (Sept – Oct) | 96 (66%) | 170 (72%) | ||
| Late Fall (Nov – Dec) | 32 (22%) | 39 (17%) | ||
|
| ||||
| Number of Controls per Case | 1 | 54 (37%) | ||
| 2 | 91 (63%) | |||
|
| ||||
| Time from specimen collection date of case and matched controls | ≤ 14 days | 193 (82%) | ||
| 15 – 30 days | 14 (6%) | |||
| 31 – 60 days | 13 (5%) | |||
| ≥ 60 days | 16 (7%) | |||
|
| ||||
| Number and % of cases without an interview of the case-proxy | 43 (29.7%) | |||
|
| ||||
| Diagnostic Test for Influenzad | Culture | 28 (19%) | 10 (4%) | |
| PCR | 98 (68%) | 209 (89%) | ||
| Rapid enzyme immunoassay | 16 (11%) | 15 (6%) | ||
| Fluorescent AB | 3 (2%) | 2 (1%) | ||
a
Twelve outpatient controls did not have a chart review completed and sex was not determined.
b
Residence type only available on 88 (61%) of the cases and 210 (89%) of the controls.
c
22 persons listed “Hispanic” as their race and one person listed “Filipino”
d
Results reflect medical chart review results. All controls were reported to the state health department as having a positive culture or PCR for pH1N1.