Assessing the stages of the grieving process in chronic obstructive pulmonary disease (COPD): validation of the Acceptance of Disease and Impairments Questionnaire (ADIQ).

Background: Patients with chronic obstructive pulmonary disease (COPD) encounter many (gradual) losses due to their disease, which trigger a grieving process. This process is characterized by stages of denial, resistance, sorrow, and acceptance.
Purpose: This study examined whether these stages are conceptually distinct and whether the Acceptance of Disease and Impairments Questionnaire (ADIQ) can validly and reliably measure these stages in three samples of patients with COPD in the Netherlands.
Methods: Exploratory factor analysis (EFA) was performed on 145 outpatients with moderate to severe COPD. Confirmatory factor analyses were performed on 303 outpatients with mild to very severe COPD and 127 patients entering an inpatient pulmonary rehabilitation program. Furthermore, internal reliability, construct validity, sensitivity to change, and floor and ceiling effects were examined.
Results: EFA yielded a four-factor solution that explained 73.2 % of variance. Confirmatory factor analyses showed a good fit of the four-factor structure in all study samples. Cronbach's alpha reliability coefficients were .79 or higher. Subscales showed to be sensitive to change.
Conclusions: Four distinct stages of grief are recognized in COPD. The ADIQ is a valid and reliable instrument to measure these stages: denial, resistance, sorrow, and acceptance. Measuring the stages of grieving is important for disease management: addressing patients with a specific therapeutic approach for the stage they are in could help to motivate patients to engage in self-management and change their lifestyle.