Table 2

Unadjusted odds ratios for pH1N1 influenza acquisition for various potential risk factors in adults and children
Adults Children
Variable OR (95% CI) OR (95% CI)
Ethnicity* White ref ref
East/Southeast Asian 1.33 (0.69-2.56) 2.39 (1.14-5.01)
South Asian 3.07 (1.42-6.63) 1.72 (0.86-3.45)
Black 4.50 (1.57-12.87) 4.38 (1.62-11.84)
Other 1.21 (0.59-2.46) 2.84 (1.33-6.08)
Age 18-34 ref <5 0.45 (0.26-0.79)
35-49 0.83 (0.52-1.34) 5-11 1.39 (0.79-2.43)
50-64 0.71 (0.42-1.20) 12-17 ref
65+ 0.64 (0.29-1.39)
Gender (Female) 0.93 (0.62-1.39) 0.90 (0.55-1.47)
BMI class II (18.5 ≤ BMI <25) ref ref
III (25 ≤ BMI < 30) 1.23 (0.77-1.96) 1.48 (0.61-3.60)
IV (BMI ≥ 30) 1.31 (0.76-2.26)
Current smoker 0.68 (0.43-1.07) 0.96 (0.91-1.02)
Number of visits to family doctor in the past year Low (<=1) 0.90 (0.53-1.54) 1.49 (0.83-2.69)
Moderate (2–6) ref ref
High (>6) 1.81 (1.07-3.07) 1.07 (0.61-1.90)
Underlying medical conditions 1.51 (0.93-2.44) 0.81 (0.44-1.48)
Material deprivation 1 (low) ref ref
2 1.76 (0.96-3.19) 1.07 (0.54-2.10)
3 1.49 (0.78-2.85) 1.11 (0.55-2.22)
4 2.11 (1.08-4.11) 1.55 (0.76-3.17)
5 (high) 1.23 (0.65-2.31) 1.22 (0.58-2.56)
Social deprivation 1 (low) ref ref
2 1.23 (0.65-2.34) 1.18 (0.63-2.23)
3 0.87 (0.46-1.63) 1.09 (0.56-2.13)
4 0.82 (0.45-1.52) 1.12 (0.57-2.20)
5 (high) 0.76 (0.39-1.46) 1.21 (0.56-2.61)
Total deprivation category 1 (low) ref ref
2 0.78 (0.46-1.33) 1.30 (0.76-2.23)
3 (high) 0.91 (0.44-1.87) 2.04 (0.88-4.75)
Individuals living in a neighbourhood with low employment rate§ 0.84 (0.52-1.36) 1.37 (0.73-2.60)
Individuals residing in a neighbourhood with a high proportion of low income§ 1.05 (0.67-1.66) 2.60 (1.36-4.96)
High school or less education 0.85 (0.48-1.50) 1.09 (0.58-2.06)
Post-secondary school completion 0.82 (0.54-1.24) 1.21 (0.74-1.98)
Household densityǁ 1.26 (0.84-1.87) 1.81 (0.95-3.44)
Children in household 1.70 (1.13-2.53) 1 ref
2 1.02 (0.59-1.75)
>3 1.14 (0.46-2.87)
Receipt of 2008 seasonal vaccine 1.25 (0.84-1.88) 1.96 (1.16-3.31)
Tested prior to June 11th, 2009 0.12 (0.07-0.21) N/A
Healthcare provider 1.51 (0.83-2.77) N/A
Toronto 0.47 (0.30-0.74) 1.07 (0.62-1.83)
Immigrant category
Non-Immigrant ref ref
Immigrant N/A 2.52 (1.02-6.25)
Immigrant, Settled for 0–5 years 2.40 (1.01-5.68) N/A
Immigrant, Settled for >5 1.16 (0.75-1.80) N/A

*This was based on the question “People in Canada come from many different ethnic and racial backgrounds. I would like you to identify which ethnicity best describes you. You may choose more than one category.” The ethnic groupings were based on the categories similar to Statistics Canada definitions.

Underlying medical conditions for adults was having at least one of the following: diabetes, cancer, heart disease, asthma, chronic obstructive pulmonary disease (COPD), immune disorder, liver disease, kidney or renal disease, splenectomy, sickle cell anemia, seizure disorder, leukemia, cystic fibrosis, or cerebral palsy. In children, underlying medical conditions was having either asthma or immune disorder.

Material Deprivation was based on employment to population ratio, average income and proportion without high school diploma. Social deprivation was based on proportion of persons living alone; proportion separated, divorced or widowed; and proportion of single-parent families. Quintiles of material and social deprivation were created based on dissemination areas in Ontario, with a score of 1 representing low deprivation and 5 indicating high deprivation. The material and social deprivation were combined to form a total deprivation score, which was categorized as high, middle or low deprivation.

§Low employment rate and High Proportion of Low Income are based on individuals residing in a dissemination area in Ontario. Individuals living in a neighbourhood in the bottom quintile of all dissemination areas for low employment/with high proportion of low income, based on our study population, were classified as being in the low employment rate/high proportion of low income categories.

ǁCalculated as the number of people in the household divided by the number of sleeping rooms in the household.

Healthcare provider is defined as a doctor, nurse or another healthcare professional.

N/A = Not applicable.

Navaranjan et al.

Navaranjan et al. BMC Public Health 2014 14:214   doi:10.1186/1471-2458-14-214

Open Data