Volume 30, Number 1—January 2024
Research
Population-Based Study of Pertussis Incidence and Risk Factors among Persons >50 Years of Age, Australia
, Ken L. Chin, Adrienne Guignard, Leah-Anne Latorre, C. Raina MacIntyre, Brittany Schoeninger, and Sumitra Shantakumar
Table 2
Predictors of pertussis in persons ≥50 years of age from conditional univariable logistic regression models in the overall study population, Australia*
| Variable | OR (95% CI) | p value |
|---|---|---|
| Smoking status | ||
| No | Referent | |
| Yes |
1.18 (0.88–1.58) |
0.80 |
| Alcohol consumption/d† | ||
| None | Referent | |
| ≤1 unit | 1.02 (0.71–1.46) | 0.93 |
| >1 unit |
1.04 (0.67–1.63) |
0.86 |
| Immunization history‡ | ||
| Pertussis | 0.77 (0.48–1.24) | 0.28 |
| Influenza | 0.52 (0.37–0.73) | <0.001 |
| Pneumococcal |
0.70 (0.41–1.17) |
0.17 |
| Comorbidities§ | ||
| CVD | 1.30 (0.97–1.74) | 0.08 |
| Heart failure | 0.93 (0.33–2.63) | 0.90 |
| Diabetes mellitus | 1.65 (1.13–2.42) | <0.001 |
| Stroke | 0.88 (0.32–2.42) | 0.80 |
| Chronic kidney disease | 0.90 (0.42–1.92) | 0.78 |
| Cancer | 1.45 (0.98–2.15) | 0.06 |
| Asthma | 2.46 (1.54–3.93) | <0.001 |
| COPD | 2.01 (1.38–2.93) | <0.001 |
| Asthma/COPD |
2.2 (1.59–3.05) |
<0.001 |
| Use of ACEi-ARB | 1.45 (1.09–1.93) | <0.001 |
| Prior use of antibiotics | 7.19 (4.42–11.69) | <0.001 |
*Variables were defined as those at baseline (i.e., restricted to those recorded during the study period or until the time of pertussis diagnosis). In this analysis, patients with missing data were excluded. ACEi-ARB, angiotensin-converting enzyme inhibitors–angiotensin receptor blockers; COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease (except heart failure); OR, odds ratio. †One unit of alcohol is defined as containing 10 g of alcohol. ‡History of pertussis immunization was defined as the presence of pertussis immunization record throughout the study period, as recorded in the Australia general practitioner electronic medical records database. §History of CVD, chronic kidney disease, and cancer were defined as those at baseline and were restricted to those recorded during the study period, or until the time of pertussis diagnosis, as applicable.