Table 1 Device attributes and utility levels included in the interview
Device attributeUtility levelDevice attributeUtility level
Bruising*Almost noneTelephone helpline24 h a day
A littlefrom 9 am to 5.30 pm
Operated byButton – automatic injectionInjectionWithout a needle
Pushing plunger (like a syringe)With 0.5 cm long needle
Pain felt*Slight twingeWith 1 cm long needle
Distinct pinchSize9 cm×3 cm
Like blood test9 cm×6 cm
WeightLike a pencil (10 g)15 cm×6 cm
Like half an apple (50 g)15 cm×9 cm
Like a standard apple (100 g)Nurse support at homeAvailable
Like a large apple (150 g)Not available
Sound madeNoneNeedle visibilityHidden/not used
Soft (heard by user only)A little visible
Distinct (heard within 2–3 m)Clearly visible
Loud (heard by all those in same room)StoredIn the fridge
PreparationNo mixing requiredAt room temperature
Mixing required weekly-to-monthlyMedicineDelivered to home
Ease of holding*Very easy – adults/older childrenAvailable from local chemist
Very easy – adults
Fairly easy – adult
  • *Attributes marked with an asterisk were not included within the model and hence did not influence the choice based analysis.