1.
Assessing quality of life in adult growth hormone deficiency: Further
development of the QoL-AGHDA
Graham JE, McKenna SP, Wilburn J, Twiss J.
Galen Research Ltd, Manchester, UK
Background
The QoL-AGHDA is included in a large international database
monitoring long-term efficacy and safety of growth hormone
replacement therapy. Thus, demand for the QoL-AGHDA has led
to the development of 15 new language versions of the measure
for Europe (13) and North America (2).
Recently, the QoL-AGHDA was required for use in two new major
multinational clinical trials. These required the development of
additional language versions for Greece, Hungary, Israel,
Romania, Russia, Slovakia, Ukraine and Spanish for the US.
This poster reports on the new language adaptations.
Table 1: QoL-AGHDA language versions available
America USA
23 language versions of the QoL-AGHDA are now available.
The standards set by the UK version of the QoL-AGHDA are high,
demonstrating excellent psychometric and scaling properties.
Completed validations have obtained a similar psychometric quality.
Studies are currently underway to evaluate the formal construct
validity and reproducibility of these new language versions.
Methodology
Figure 2: International coverage of the QoL-AGHDA
Contact details
Miss Jessica Elizabeth Graham. Research Assistant, Galen Research Ltd, Enterprise House, Manchester Science Park, Lloyd Street North, Manchester, M15 6SE, UK.
Tel: +44 (0)161 226 4446
Email: jgraham@galen-research.com
(English)
USA
(Spanish)
Brazil
(Portuguese)
Europe Belgium
(Flemish)
Belgium
(French)
Czech Rep.
(Czech)
Germany
(German)
Serbia
(Serbian)
Denmark
(Danish)
Spain
(Spanish)
France
(French)
Italy
(Italian)
Netherlands
(Dutch)
Poland
(Polish)
Sweden
(Swedish)
Slovakia
(Slovakian)
UK
(English)
Greece
(Greek)
Hungary
(Hungarian)
Romania
(Romanian)
Russia
(Russian)
Ukraine
(Ukrainian)
Israel
(Hebrew)
The concept of Quality of life (QoL) is beset with theoretical
disagreement. This problem is confounded by the fact that few
‘QoL’ measures are based on a clear theoretical model. By
contrast, the QoL-AGHDA adopted the needs-based QoL model
(see below).
Health authorities now require evidence of patient benefit in
addition to evidence of safety and efficacy. This has led to an
increase in the importance of having available high quality patient
-reported outcome (PRO) measures.
When used in clinical trials, PROs need to demonstrate extremely
good psychometric properties, including: unidimensionality,
reproducibility, construct validity and responsiveness to change.
The needs-based QoL model argues that QoL is dependent on the ex-tent
to which a patient’s needs are satisfied. If needs are not met, QoL
is poor. Disease (and potentially its treatment) prevent needs from be-ing
fulfilled.
Hunt SM, McKenna SP. The QLDS:A scale for the measurement of
quality of life in depression. Health Policy 1992a;22: 307-19.
The QoL-AGHDA was first published in 1999 and has been
regularly used in clinical studies ever since.
McKenna SP, Doward LC, Alonso J, Kohlman, T, Neiro M, Preito L, Wiren, L.
(1999). The QoL-AGHDA: An instrument for the assessment of quality of life
in adults with growth hormone deficiency. Quality of life research, 8, 373-383
To derive the content of the QoL-AGHDA, qualitative interviews
were conducted with GHD patients. Initially, 37 items were
chosen as being relevant to the UK, Sweden, Germany, Italy and
Spain. A test-retest postal survey was conducted to reduce the
measure, establish its psychometric properties and to ensure
unidimensionality. Items with low item-total correlations were
removed, producing a 25-item version of the QoL-AGHDA. This
version had excellent internal consistency (=0.88-0.94) and test-retest
reliability (0.86 – 0.95) in all five countries. Construct
validity was demonstrated by the measure’s ability to distinguish
between patients according to self-perceived general health in
Spain, and by correlating scores with those on the General Well
Being Index (0.70) for the UK, Sweden and Germany.
The QoL-AGHDA is well accepted by patients. It is short, easy to
administer and complete and has excellent scaling properties.
Thus, it is a practical and valuable measure for assessing the
impact of interventions for GHD in clinical studies and trials.
No major difficulties were experienced in producing the
translations. Ten to fifteen patient interviews were conducted in
each country. Interviewees confirmed that the adapted measures
are simple, easy to understand and idiomatic. The content of the
measure was deemed acceptable and relevant to patients with
GHD, without missing any important issues.
Table 1 shows the available QoL-AGHDA language versions.
Geographical coverage is shown in Figure 2.
Please contact the authors at the address below if you are interested in further validating existing versions of the
QoL-AGHDA or collaborating on the development of new language versions. Thank you.
Objectives
A dual-panel methodology was employed to translate the
measures.
This methodology emphasises the importance of conceptual
equivalence rather than simply producing a literal translation of
the item. Initially, members of a bilingual panel suggest possible
translations. A lay panel is then convened consisting of local
people of average education who check the translations and can
change the wording to ensure it is easy to understand. Thus,
final wording is at an appropriate level of sophistication for
potential patients.
Finally, the translations were tested with local GHD patients by
means of cognitive debriefing interviews. These interviews were
designed to confirm face and content validity.
Results
Conclusions
Figure 1: Sample page from the QoL-AGHDA