RELIABILITY AND VALIDITY OF THE GERMAN VERSION OF THE SICKNESS IMPACTPROFILE IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

Reliability and validity of the German version of the Sickness Impact Profile (SIP) were investigated in a sample of 58 O-2-dependent patien ts with chronic obstructive pulmonary disease (COPD). Internal consist ency (Cronbach Alpha) was .93 for the entire instrument, while it was .85 for the SIP psyche-social scab and .89 for the SIP physical scale. The Cronbach Alphas ranged from .55 to .86 for the subscales of the G erman SIP version. The subscale ''Eating'' was discarded because of lo w internal consistency (.40) and split-half reliability (.24). Indices of respiratory function (FEV(1), FVC, PaO2, SaO(2)), functional impai rment and dyspnea (BDI) were substantially associated with the total S IP, psychosocial and physical score, ranging from r = -.33 to r = -.48 . A stepwise discriminant analysis between the 14 patients, who died d uring the course of the study and the survivors revealed one single di scriminant function with an Eigenvalue of .5859 (canonical correlation r = .61; Chi(2) = 21.21; df = 3; p < 0.001). The FVC (Wilk's Lambda . 76), the severity of dyspnea (BDI) (Wilk's Lambda .71), the SIP total score (Wilk's Lambda of .65) and the FEV(1) (Wilk's Lambda .63) were i dentified as discriminating variables, allowing the correct classifica tion of 85% of the survivors and 91% of the fatalities.