Introduction
Common variable immunodeficiency (CVID) is the most frequent and
commonly diagnosed symptomatic primary immune deficiency disorder in
adults 1 with prevalence ranging from 1 in 10 000 to 1
in 50 000 in different populations 2. CVID is
characterized by various clinical conditions such as severe infections,
malignancy, granulomatous and autoimmune disorders 1.
Although some patients have symptoms from early childhood, the
distinguishing feature of CVID is primary hypogammaglobulinemia caused
by late onset antibody failure 3. Immunoglobulin (Ig)
replacement is the main treatment for the prevention of recurrent
infections, and it can decrease frequency of bacterial infections
however, it is less effective on other CVID associated complications4, 5.
Patient-focused assessment methods have become more important in the
follow-up of the patients with chronic diseases 6. In
addition, this approach strengthens the relationship between the doctor
and the patient, makes some problems visible that are not noticed
routinely and enables better follow-up of diseases and treatments7. In very few studies analysing the psychosocial
aspects of CVID, patients are not homogenous group as shown for other
chronic diseases 8. In addition, there is a lack of
knowledge about one of the rare diseases CVID which has different
psychological and social effects both in society, individuals and
healthcare providers 9. In recent years, with
considerable progress in early diagnosis, increased awareness and Ig
replacement therapy led to a significantly extended life expectancy for
patients with primary antibody deficiencies10.
Ever since the World Health Organization defined health not only as the
absence of disease and illness, but also as the presence of physical,
mental and social well-being, questions of quality of life have become
increasingly important in health practice and research11. In healthcare, QoL is an assessment of how
different aspects of an individual’s life can be affected by a disease
or a disability 12. It is a comprehensive concept that
is important to evaluate the impact of disease, treatment and symptoms13. QoL is an important health outcome representing
the ultimate goal of all health interventions and the use of valid and
reliable measurements is essential for providing evidence-based health
care 14.
Clinicians mostly deal with more objective data of their patients and
whether their illness is cured. QoL scales are mostly used for research
purposes and are very rare examples in routine clinical practice. There
are many different quality of life scales that contain questions about
different aspects of life (environment, social, economics, etc…) that
can be used with patients and healthy populations 14.
The tools for measuring QoL can be divided into 2 groups: generic and
specific. Generic scales can be applied to all kinds of patients and
healthy groups including general questions that are not specific to the
disease. Specific scales focus on a group or single illness or symptom15. Because generic QoL scales may not capture the
positive and negative effects of some specific limitations and effects
of each disease and each disease may have specific clinical features and
mental effects, it is more appropriate to use validated disease-specific
scales.
The measurement of health-related quality of life (HRQoL) in primary
immunodeficiency has arisen relatively recently from an effort to
document the outcome of therapeutic intervention and the need to obtain
information about patients’ well-being as well as objective findings
visible to physicians 16. On the other hand, CVID
manifestations which are the findings of more common diseases and have
been frequently investigated but the knowledge about the effects of Ig
replacement therapy on patients is insufficient. Thus, development and
validation of a disease-specific HR-QoL survey tool and researchers’
understanding of the quality of life of CVID patients is necessary.
In previous studies, generic health status QoL scales were used such as
Short form (SF-36, SF-12) and General Health Questionnaire (GHQ-12) in
adult CVID population 16-18. The need for a specific
QoL scale that includes better questions has arisen because it can
provide the features of CVID more accurately. Quinti et al developed the
CVID specific QoL questionnaire in 2015 10 and it was
used in scientific studies in Norway and Italy 19, 20.
The aim of this study was to translate this Italian CVID QoL scale to
Turkish and investigate the validity and usefulness of CVID QoL
questionnaire and determine the impact of CVID on quality of life for
use with adult CVID patients by healthcare professionals and
researchers.