Hazard ratio (HR) for the time to first exacerbation was the lowest in the HP+/AZ group after adjusting for age, sex, smoking status, ethnicity, history of peptic ulcer, dyspnea, previous hospital admission for COPD during past year, GOLD grade of severity of airflow limitation, and FVC (HR, 0.612; 95% CI, 0.442–0.846; p = 0.003 vs HR, 0.789; 95% CI, 0.663–0.938; p = 0.007 in the HP-/AZ group vs HR, 1.096; 95% CI, 0.832–1.442; p = 0.52 in the HP+/PL group vs HR, 1 in the reference group [HP-/PL]). The gene discussed is HP; the disease is chronic obstructive pulmonary disease.