Introduction
Methods
Design, quality and ethical conduct
STEP I: concept elicitation
Literature review
Item generation interviews and questionnaire development
1 – Not at all Important | 2 – Slightly Important | 3 - Moderately Important | 4 - Important | 5 – Very Important | 6 – Does not apply to me | |
---|---|---|---|---|---|---|
How important is it to you that the treatment enables... | ||||||
to be less depressed and restores your zest for life | □ | □ | □ | □ | □ | □ |
to feel good every day | □ | □ | □ | □ | □ | □ |
to continue to work | □ | □ | □ | □ | □ | □ |
not to fear the administration of your treatment | □ | □ | □ | □ | □ | □ |
to be able to spend time with your family | □ | □ | □ | □ | □ | □ |
to stop the evolution of Fabry disease | □ | □ | □ | □ | □ | □ |
not to cause excessive sweating | □ | □ | □ | □ | □ | □ |
to reduce pain in the feet | □ | □ | □ | □ | □ | □ |
to have less mood swings | □ | □ | □ | □ | □ | □ |
not to suffer from side effects or adverse events related to treatment | □ | □ | □ | □ | □ | □ |
… | □ | □ | □ | □ | □ | □ |
How important is it to you to have a treatment... | ||||||
that you can pick up at the pharmacy in your town | □ | □ | □ | □ | □ | □ |
… | □ | □ | □ | □ | □ | □ |
STEP II: psychometric analysis and cognitive validation
Participants and study centres
Data collection
Psychometric and cognitive validation procedures
Content validity
Comprehensibility validity
Completeness validity
Internal consistency
Structural validity
STEP III: quantitative reliability testing
Reliability
Supplementary validation compared with a validated PRO (WHOQOL-BREF)
Results
STEP I: concept elicitation
Literature review
Concept elicitation interviews and building of the conceptual framework
STEP II: psychometric analysis and cognitive validation
Content validity
Comprehensibility validity
Completeness validity
Internal consistency
Structural validity
How important is it to you that the treatment … | ||||||
Please tick a box for each statement | Not at all important | Slightly important | Moderately important | Fairly important | Very important | Does not apply to me |
ensures you feel less tired | □ | □ | □ | □ | □ | □ |
reduces the pain in your hands and feet | □ | □ | □ | □ | □ | □ |
ensures you are less breathless when performing daily activities or with strenuous activities | □ | □ | □ | □ | □ | □ |
reduces gastrointestinal disorders (nausea, pain, diarrhoea, constipation) | □ | □ | □ | □ | □ | □ |
enables you to tolerate variations with heat and temperature better | □ | □ | □ | □ | □ | □ |
reduces the intensity, frequency, or duration of painful attacks | □ | □ | □ | □ | □ | □ |
enables you to continue working | □ | □ | □ | □ | □ | □ |
enables you to cope with physical exertion better | □ | □ | □ | □ | □ | □ |
enables you to live normally, as if you did not have Fabry disease (handicraft, housework, gardening, playing with your children, grandchildren.) | □ | □ | □ | □ | □ | □ |
enables you to maintain your social life (work, school, family, friends.) | □ | □ | □ | □ | □ | □ |
enables you to travel easily | □ | □ | □ | □ | □ | □ |
enables you to have a better quality of life | □ | □ | □ | □ | □ | □ |
ensures you are not dependent on other people on a daily basis | □ | □ | □ | □ | □ | □ |
enables you to spend time with your family | □ | □ | □ | □ | □ | □ |
enables you to stay fit for longer | □ | □ | □ | □ | □ | □ |
prevents the onset of heart, kidney, or neurological problems | □ | □ | □ | □ | □ | □ |
slows down the deterioration of your organs (kidneys, heart, brain.) | □ | □ | □ | □ | □ | □ |
enables you to feel good every day, even on days preceding or following treatment administration | □ | □ | □ | □ | □ | □ |
does not cause side effects or adverse effects related to the medication | □ | □ | □ | □ | □ | □ |
ensures you do not experience pain and tiredness returning on days before medication is administered | □ | □ | □ | □ | □ | □ |
reduces the amount of medication that you are taking | □ | □ | □ | □ | □ | □ |
How important is it to you to have a treatment … | ||||||
Please tick a box for each statement | Not at all important | Slightly important | Moderately important | Fairly important | Very important | Does not apply to me |
that easily fits into your schedule and lifestyle | □ | □ | □ | □ | □ | □ |
that you can take or administer on your own | □ | □ | □ | □ | □ | □ |
that is easy to administer | □ | □ | □ | □ | □ | □ |
that is administered orally (in tablet or capsule form) | □ | □ | □ | □ | □ | □ |
with a short duration of administration | □ | □ | □ | □ | □ | □ |
STEP III: quantitative reliability testing
Calculated for each item | PNQ Fabry | WHOQOL-BREF |
---|---|---|
% Minimal of deviation =0 observed for one item | 52.6% | 46.1% |
% Maximal of deviation =0 observed for one item | 93.4% | 73.7% |
Mean of % deviation =0 | 72.7% | 63.0% |
Calculated for each item | PNQ Fabry | WHOQOL-BREF |
---|---|---|
% Minimal of deviation [−1; + 1] observed for one item | 78.9% | 73.7% |
% Maximal of deviation [−1; + 1] observed for one item | 98.7% | 97.4% |
Mean of % deviation [−1; + 1] observed for all items | 90.9% | 90.5% |
Calculated for each item (rating /5) | PNQ Fabry | WHOQOL-BREF |
---|---|---|
Minimal difference observed for one item | −0.15 | −0.18 |
Maximal difference observed for one item | 0.19 | 0.16 |
Sum of absolute values of differences observed in all items | 0.34 | 0.34 |
Mean of absolute values | 0.09 | 0.06 |
Calculated for each item | PNQ Fabry | WHOQOL-BREF |
---|---|---|
% Minimal difference observed for one item | −3.95 | −2.63 |
% Maximal difference observed for one item | 3.95 | 5.26 |
Sum of absolute values of differences observed in all items | 7.90 | 7.89 |
Mean of absolute values | −0.10 | −0.20 |