Volume 11, Number 2—February 2005
Perspective
Managing Febrile Respiratory Illnesses during Hypothetical SARS Outbreaks
, Peter Muennig†, Michael Gardam‡, and Joshua Graff Zivin†
Table 2
Selected probabilities in the decision-analysis model*
| Selected probabilities | Low | Base | High | Source |
|---|---|---|---|---|
| Diagnostic tests | ||||
| Sensitivity of influenza test | 0.50 | 0.70 | 0.90 | 19 |
| Specificity of influenza test | 0.80 | 0.95 | 0.99 | 19 |
| Sensitivity of multiplex† RT-PCR | 0.70 | 0.85 | 0.95 | 20–22 |
| Specificity of multiplex† RT-PCR | 0.80 | 0.987 | 0.99 | 20–22 |
| Sensitivity of SARS‡ RT-PCR | 0.25 | 0.70 | 0.95 | 4,23 |
| Specificity of SARS‡ RT-PCR | 0.95 | 0.994 | 1.00 | 23,24 |
| Morbidity and mortality | ||||
| Hospitalization due to influenza | 0.002 | 0.004 | 0.01 | 25 |
| Death due to influenza | 0.0 | 0.0012 | 0.01 | 25,26 |
| Hospitalization due to FRI | 0.010 | 0.015 | 0.02 | Calculated |
| Death due to FRI | 0.0 | 0.0009 | 0.01 | Calculated |
| Death due to SARS | 0.10 | 0.15 | 0.20 | 24 |
| Miscellaneous probabilities | ||||
| Probability of an FRI | 0.10 | 0.33 | 0.50 | 27 |
| Due to influenza | 0.20 | 0.33 | 0.50 | 11,25,27,28 |
| Due to multiplex† organisms other than influenza | 0.20 | 0.33 | 0.50 | 29,30 |
| Due to other causes§ | 0.20 | 0.33 | 0.50 | Calculated |
| Due to SARS | 0.0 | 0.0001 | 0.01 | Assigned |
| Influenza vaccine effectiveness | 0.35 | 0.67 | 0.85 | 31 |
| Annual probability of poor match between vaccine and circulating influenza strains | 0.05 | 0.20 | 0.50 | 31 |
| Probability of successful self-care management of an FRI at home | 0.33 | 0.67 | 1.00 | Assumption |
| Probability of receiving outpatient antimicrobial drugs for an FRI | 0.33 | 0.67 | 1.00 | 32 |
| Miscellaneous values | ||||
| Patient time for outpatient medical visit (min) | 30 | 50 | 90 | Estimate |
| Influenza length of illness (d) | 3 | 7 | 10 | 31 |
| Other FRI¶ length of illness (d) | 1 | 3 | 5 | Estimate |
| Average duration of hospitalization, influenza (d) | 5 | 10.2 | 15 | 14 |
| Average duration of hospitalization, FRI¶ (d) | 3 | 7.7 | 10 | 14 |
| Average duration of hospitalization, SARS (d) | 10 | 16 | 30 | 15 |
| HRQL scores | ||||
| SARS, hospitalized | 0.05 | 0.160 | 0.50 | HUI |
| SARS, outpatient | 0.25 | 0.670 | 0.75 | HUI |
| SARS, contact | 0.50 | 0.785 | 0.95 | HUI |
| FRI, hospitalized | 0.25 | 0.511 | 0.75 | HUI |
| FRI, outpatient | 0.50 | 0.804 | 0.95 | HUI |
| Reproductive number for SARS# | 2 | 3 | 4 | 9,10 |
| Contact investigations (per SARS case) | 25 | 50 | 100 | 5 |
*RT-PCR, reverse transcriptase–polymerase chain reaction; SARS, severe acute respiratory syndrome; FRI, febrile respiratory illness; HRQL, health-related quality of life; HUI, Health Utilities Index.
†Refers to influenza viruses A and B, respiratory syncytial viruses A and B, parainfluenza viruses 1–3, human metapneumovirus, Legionella pneumophila, L. micdadei, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Bordetella pertussis.
‡Detects SARS-associated coronavirus and coronaviruses OC43 and 229E.
§Febrile respiratory illnesses not due to SARS, influenza viruses A and B, respiratory syncytial viruses A and B, parainfluenza viruses 1–3, human metapneumovirus, L. pneumophila, L. micdadei, M. pneumoniae, C. pneumoniae, and B. pertussis.
¶Febrile respiratory illnesses not due to SARS or influenza viruses A and B.
#In the absence of public health interventions.