Page 146 - Comprehensive treatment of patients with glucocorticoid-dependent severe asthma
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Chapter 9
Statistical analysis
At baseline we described groups in terms of sociodemographic factors, history of asthma, asthma control (ACQ), lung function and airway inflammation (FeNO). For continuous variables we used means with standard deviations if normally distributed and medians with 25th-75th percentiles if non-normally distributed data, for categorical variables we used percentage of total number. Adherence, reliability, sparing dose of prednisone and costs were analyzed as continuous variables.
Linear regression analysis was used to assess the relationship between adherence vs sparing dose of prednisone and adherence vs the costs associated to health care events. Patient’s gender, age and ACQ score at baseline were entered as covariates in all regression models due to the possible effect of these characteristics in the adherence [30].
All p-values are two-sided and if below 0.05 the results were considered statistically significant. Analyses were conducted using PASW Statistics 19.0 (SPSS, Inc., Chicago, IL, USA).
Results
A total of 52 patients started in the internet based study (November 2007 to October 2008), from these 48 patients completed the visits. Forty-three patients (19 male, age 50.1 ± 11.2 (mean ±SD)) were included in the analysis, with correspondent FeNO values retrieved from the memory cards and completed questionnaires evaluating costs and burden of asthma (Figure 1). The baseline characteristics from these patients are outlined in Table 1.
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