Figure 1From: Daily activity during stability and exacerbation of chronic obstructive pulmonary disease Daily step-count of 33 infrequent (number of days with data = 6878) and 40 frequent (number of days with data = 7775) exacerbators; predicted values obtained from the random effects, linear regression model (test of interaction, p = 0.002). Time 0 corresponds to the start of the study.Back to article page