The Infant health-related quality of life Instrument (IQI): Valuing health status in the first year of life

Karin M. Vermeulen, Ruslan Jabrayilov, Livia Dainelli, Patrick Detzel, Antoinette D.I. Van Asselt, Paul F.M. Krabbe

Research output: Contribution to journalMeeting AbstractAcademic

2 Citations (Scopus)


Aims: The lack of preference-based HRQoL instruments for infants up to 12 months of age hampers evaluating HRQoL and calculating quality-adjusted life years (QALYs) for this population. To fill this gap, we developed the Infant Quality of life Instrument (IQI). We explain the development of the IQI, how the weights are derived and how to generate utilities. Methods: Candidate health concepts were extracted from relevant instruments identified by literature search. Expert panels and surveys with primary caregivers evaluated the relevance of these concepts, organized them based on their similarities, explored alternatives and generated response scales. Additional interviews assessed cross-cultural interpretability and parents' understanding, and the functionality of the mobile application. Next, respondents from the general population (n = 1409) and primary caregivers (n= 1229) from China, UK and USA were presented with 10 discrete choice scenarios based on the IQI classification system. Coefficients for the item levels were obtained with a conditional logit model. Respondents were also asked if they considered the health states worse than dead. Coefficients were normalized by using a rankordered logit model. In this way the values were rescaled to be ranging from full health (1.0) to dead (0.0), and consequently suitable for QALY computation. Results: The final instrument consists of 7 health attributes sleeping, feeding, breathing, stooling/poo, mood, skin, and interaction. All attributes had 4 response levels. Sleeping, feeding and breathing were the most important items for both general population as well as primary caregivers. Based on the coefficients, predicted values for all possible health states were calculated. No health states in the complete set of possible health states had a value below 0, as indicated by the normalized results. Conclusions: The IQI is the first generic instrument to assess overall HRQoL in 0-1-year old infants providing a value for health status. It is short and easy to administer with a mobile application. We demonstrated that it is possible to derive values of infant health states by using discrete choice experiments, and to define an anchor point based on states worse than dead. Next step is to collect IQI values in a clinical population of infants.
Original languageEnglish
Pages (from-to)147-148
Number of pages2
JournalQuality of Life Research
Publication statusPublished - 1-Oct-2018


  • breathing
  • caregiver
  • child health
  • China
  • conference abstract
  • controlled study
  • feeding
  • female
  • health status
  • human
  • infant
  • interview
  • major clinical study
  • male
  • mobile application
  • mood
  • population
  • quality adjusted life year
  • skin
  • sleep


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