Volume 20, Number 9—September 2014
Dispatch
Risk Factors for Severe Influenza A–Related Pneumonia in Adult Cohort, Mexico, 2013–14
Table 2
Characteristics | 2009–10, n = 100 | 2013–14, n = 55 | p value |
---|---|---|---|
Age, y, mean (SD) median (range) | 38.9 (13.1), 37 (15–71) | 46.1 (14), 45 (19–79) | 0.002 |
Sex, no. (%) | |||
M | 52 (52) | 28 (50.9) | 0.89 |
F | 48 (48) | 27 (49.1) | |
Presence of ≥1 underlying conditions, no. (%) | 68 (68) | 47 (85.5) | 0.017 |
Obesity (body mass index>30)† | 39 (39.8) | 40 (74.1) | <0.001 |
Diabetes mellitus | 20 (20) | 15 (27.3) | 0.3 |
Immunosuppression | 8 (8) ‡ | 3 (5.5) § | 0.75 |
Asthma-COPD-bronchiectasis | 9 (9) | 2 (3.6) | 0.33 |
Other | 19 (19) | 4 (7.3) # | 0.049 |
Any underlying disorder excluding obesity, no. (%) | 45 (45) | 23 (41.8) | 0.7 |
Influenza vaccination during most recent season, no. (%)** | 4 (4) | 3 (5.5) | 0.7 |
Clinical findings | |||
Body mass index, mean (SD) † | 28.9 (5.9) | 31.9 (3.9) | <0.001 |
PaO2/FiO2, mean (SD) †† | 152.1 (102.5) | 156.2 (69.3) | 0.32 |
Total WBCs, K/μL, mean (SD) † | 8.4 (5.3) | 6.4 (3.2) | 0.02 |
Lymphocytes, K/μL, mean (SD) ‡‡ | 0.94 (0.5) | 0.85 (0.72) | 0.37 |
C-reactive protein, mg/dL, mean (SD) § § | 14.1 (9.8) | 17.9 (10.9) | 0.03 |
Lactate dehydrogenase, U/L, mean (SD) ¶¶ | 1,099.4 (769.6) | 581.8 (387.9) | <0.001 |
Creatine phosphokinase, U/L, mean (SD) ## | 530 (820.6) | 480.6 (513.9) | 0.69 |
Duration of symptoms before dyspnea, days, mean (SD) *** | 2.1 (3.5) | 3 (3.4) | 0.13 |
Dyspnea duration before admission, days, mean (SD) ††† | 2.7 (2.7) | 3.8 (2.6) | 0.03 |
Duration of symptoms before hospital admission, days, mean (SD) ** | 4.7 (6.6) | 6.6 (3.8) | 0.003 |
Other features | |||
Requirement for mechanical ventilation, no. (%) | 47 (47) | 36 (65.5) | 0.03 |
Death within 5 d from admission, no. (%) | 6 (6) | 6 (10.9) | 0.35 |
*Statistical analyses used included Fisher exact test, chi-square test, Student t test, and Mann Whitney u test; S/D, standard deviation; COPD, chronic obstructive pulmonary disease; PaO2/FiO2, partial pressure arterial oxygen and fraction of inspired oxygen ratio; U/L, units per liter.
† Data was available for 152 patients.
‡ Includes chronic renal failure (4 cases), chronic steroid use (3 cases), and leukemia (1 case).
§ HIV infection (1 case), autoimmune disorder (2 cases; 1 had renal transplant),
¶ Some patients had >1 underlying condition: heart failure (6 cases), pregnancy/puerperium (6 cases), hypothyroidism (4 cases), seizure disorder (2 cases), ischemic cardiopathy (1 case), microcephaly (1 case), Down syndrome (1 case), obstructive sleep apnea (1 case).
# Down syndrome (2 cases); hypothyroidism (1 case), cardiopathy (1 case).
** Data available for 154 patients.
†† Data available for 147 patients.
‡‡ Data available for 151 patients.
§ § Data available for 144 patients.
¶¶ Data available for 135 patients.
## Data available for 131 patients.
*** Data available for 139 patients
††† Data available for 138 patients