Procedures
Demographic and clinical characteristics were recorded: age, gender, education level, number of infections experienced within the 3 and 12 months before participation (self- reported), disease duration, Ig levels at the time of diagnosis, the last IgG trough levels, current body mass index, route of Ig administration.
We used the short form health survey (SF-36) as a comparative questionnaire. It is a self- administered questionnaire, including 36 items Likert type or multiple-choice scale which has 8 different dimensions; physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health24. Scores for each dimension range from 0 to 100, with higher scores indicating better health.
Patients were asked “How severe is your disease?” Answers were given on a 5-point scale from 0: “very mild,” 1: “mild,” 2: “moderate,” 3: “severe,” and 4: “very severe.” The patient general assessment (PtGA) was completed before meeting the physician as were other two questionnaires. At the end of the visit, physicians also evaluated the disease severity of each patient with physician general assessment (PhGA) with the same 5- points.
Factor analyses was evaluated both QoL scores and percentages to ensure the accuracy of the analyses.
The Turkish version of CVID QoL was applied to the participants 14-21 days after the first evaluation to prove the reproducibility.
The institutional review board and the Ethics Committee of Istanbul University, Faculty of Medicine approved the study (149, 2019/ 1453) and informed consent was obtained from all study participants.