TABLE 1

Patient and physician characteristics and odds of undiagnosed and overdiagnosed chronic obstructive pulmonary disease (COPD)

CharacteristicUndiagnosed COPD#Overdiagnosed COPD
Age years1.08 (1.06–1.10)0.93 (0.89–0.98)
Male1.47 (1.02–2.08)0.79 (0.31–2.00)
Socioeconomic status quintile
 1 (lowest)Reference groupReference group
 21.29 (0.67–2.48)0.23 (0.06–0.91)
 31.10 (0.56–2.15)1.39 (0.32–6.05)
 41.59 (0.86–2.96)0.68 (0.16–2.89)
 5 (highest)1.23 (0.67–2.25)1.15 (0.30–4.45)
Body mass index kg·m−20.97 (0.94–1.00)0.98 (0.92–1.05)
Cigarette smoking pack-years
 NoneReference groupReference group
 >0 to <201.33 (0.90–1.98)0.17 (0.04–0.63)
 ≥203.77 (2.38–5.97)0.13 (0.03–0.50)
Cough, sputum, wheeze or breathlessness1.69 (1.17–2.44)0.57 (0.17–1.94)
Cardiac disease0.88 (0.59–1.31)0.98 (0.38–2.54)
Asthma2.91 (1.78–4.78)0.45 (0.16–1.29)
Overall level of comorbidity+
 LowReference groupReference group
 Intermediate or high0.56 (0.34–0.91)1.15 (0.11–11.95)
Male primary care physician0.81 (0.56–1.17)1.06 (0.37–3.08)
Primary care physician age group years
 ≤50Reference groupReference group
 >500.92 (0.65–1.31)2.79 (1.09–7.15)
Specialist care in previous 5 years1.08 (0.75–1.55)0.89 (0.34–2.34)
  • Data are presented as OR (95% CI). #: non-COPD (those without COPD by pulmonary function testing or physician diagnosis) is the reference group; : correctly diagnosed COPD is the reference group; +: determined using the Johns Hopkins Adjusted Clinical Group Case-Mix System (Johns Hopkins HealthCare Solutions, Baltimore, MD, USA). Bold indicates statistical significance with an alpha error of 0.05.