Table 6.
Multiple stepwise regression of the variables related to the total SGRQ score
| Standardized coefficients beta | t | P value | |
|---|---|---|---|
| Age | 0.07 | 0.55 | 0.59 |
| Gender | 0.30 | 2.35 | 0.023 |
| Frequency of clinic visits | 0.02 | 0.12 | 0.90 |
| Frequency of inhaler use | 0.14 | 1.03 | 0.31 |
| Type of inhaler device | 0.13 | 1.03 | 0.31 |
| Comorbidities | 0.19 | 1.35 | 0.18 |
| Antipsychotic drugs | 0.06 | 0.42 | 0.68 |
| Stage of COPD | 0.01 | 0.10 | 0.93 |
| Repeated instruction | −0.32 | −2.48 | 0.017 |
Notes: Adjusted for female sex (yes = 1, no = 0), use of DPI + MDI-type inhaler (yes = 1, no = 0), presence of comorbidities (yes = 1, no = 0), taking of antipsychotic drugs (yes = 1, no = 0), and presence of repeated instruction (yes = 1, no = 0).
Abbreviations: DPI, dry powder inhaler; MDI, metered-dose inhaler.