Factor type | Factor | Factor variable | Association highera | Association lowera | References |
---|---|---|---|---|---|
Environmental | Pollution | Particulate matter | ✓ | [28] | |
Ozone | ✓ | ||||
Climate | Low temperature/low humidity | ✓ | |||
Physiological comorbidities in adults | Immunosuppression other than HIV | renal disease, chronic disease, cancer, etc. | ✓ | [5] | |
Obesity | BMI > 30 | ✓ | |||
Morbid Obesity | BMI > 40 | ✓ | [44] | ||
Pulmonary Disease | COPD, other | ✓ | [5] | ||
Immunosupression | HIV | ✓ | [57] | ||
TB | ✓ | ||||
HIV on ARTs | ✓ | [57] | |||
Physiological comorbidities in children | Neurological Disorders | Prevalence in children | ✓ | [11] | |
Cerebral Palsy and developmental delay | ✓ | [13] | |||
Congenital Heart Disease | ✓ | [13] | |||
Asthma and immunosupression | ✓ | ||||
Treatment | Antiviral Use | Antiviral Drug Distribution | ✓ | [31] | |
Antiviral within 48 h. | ✓ | ||||
Late onset antiviral | ✓ | ||||
Healthcare | Healthcare expenditure | Access to healthcare | ✓ | ||
Prompt treatment and available options | ✓ | ||||
Physician knowledge and H1N1awareness | ✓ | ||||
Demographics | Population age structure | Preschool age | ✓ | [9] | |
Pediatric patients | ✓ | [15] | |||
% < 15 | ✓ | [16] | |||
% > 60 | ✓ | ✓ | |||
Children at home | ✓ | [34] | |||
Ethnicity | Alaskan/A.Indian/New Zealand aboriginal | ✓ | [71] | ||
Hipanics and blacks | ✓ | [13] | |||
Children of S. Asian descent | ✓ | [16] | |||
pH1N1 Viral Factors | Strain variation by country | Start of the pandemic | ✓ | ||
Pandemic peak | ✓ | ||||
Co-circulation | ✓ | ✓ | |||
Viral shedding/ transmission | Longer shedding in younger people | ✓ | [72] | ||
Longer shedding under optimal climatic conditions | ✓ | [26] | |||
Longer shedding in immunocompromised people | ✓ | ||||
Longer shedding or higher viral loads in those with severe disease | ✓ | ||||
Shorter shedding in those treated with antivirals within 48 h | ✓ | [8] | |||
Disease severity | Pathogenic strains | ✓ | |||
Data or modelling issues | Variation in case finding by country | -Clinician awareness | ✓ | ||
-Diagnostic availability | ✓ | ✓ | |||
-Testing protocol | ✓ | ✓ | |||
-Breadth of surveillance | ✓ | ✓ | |||
Pandemic preparedness activities | Policies | Quarantine | ✓ | [35] | |
Activities | Treatment, education | ✓ | |||
Case finding efforts | Outreach and method | ✓ | ✓ | ||
Quickness of response | Timing to mobilize community | ✓ | ✓ | ||
Other Factors | CDC Multiplier | [43] | |||
International flight traffic | International flights coming and going | ✓ | [36] |