Item generation for a proxy health related quality of life measure in very young children

Background and aims Very young children have a relatively high prevalence of morbidity and mortality. Health care and supportive technology has improved but may require difficult choices and decisions regarding the allocation of these resources in this age group. Cost-effective analysis (CEA) can inform these decisions and thus measurement of Health-Related Quality of Life (HRQoL) is becoming increasingly important. However, the components of HRQoL are likely to be specific to infants and young children. This study aimed to develop a bank of items to inform the possible development of a new proxy report instrument. Methods A review of the literature was done to define the concepts, generate items and identify measures that might be an appropriate starting point of reference. The items generated from the cognitive interviews and systematic review were subsequently pruned by experts in the field of HRQoL and paediatrics over two rounds of a Delphi study. Results Based on the input from the different sources, the greatest need for a new HRQoL measure was in the 0-3-year age group. The item pool identified from the literature consisted of 36 items which was increased to 53 items after the cognitive interviews. The ranking of items from the first round of the Delphi study pruned this pool to 28 items for consideration. The experts further reduced this pool to 15 items for consideration in the second round. The experts also recommended that items could be merged due to their similar nature or construct. This process allowed for further reduction of items to 11 items which showed content validity and no redundancy. Conclusion The need for an instrument to measure appropriate aspects of HRQoL in infants and young children became apparent as items included in existing measures did not cover the required spectrum. The identification of the final items was based on a sound conceptual model, acceptability to stakeholders and consideration of the observability of the item selected. The pruned item bank of 11 items needs to be subject to further testing with the target population to ensure validity and reliability before a new measure can be developed.