The strength of this study lies in the rigorous development of the satisfaction instrument through a convenience sample of parents and PICU healthcare professionals. Psychometric testing of the EMPATHIC questionnaire revealed that this instrument is reliable and valid for measuring parent satisfaction of pediatric intensive care services. The 65 statements representing five domains provide a comprehensive conceptualization of parent satisfaction. The relevance of this study is not limited to the development of an acceptable and feasible quality performance indicator for PICUs. Healthcare departments are increasingly demanding satisfaction outcomes of individual healthcare services above and beyond general hospital satisfaction measures [15
]. Besides, healthcare insurance companies increasingly demand patient satisfaction data to fund hospitals [18
]. This study provides a valuable contribution relevant to PICU colleagues in other countries and cultures. The increased need for validated instruments to collect data of patient or family experiences is evident. The challenge is to construct and design research instruments for use in study populations with different cultural backgrounds. The EMPATHIC questionnaire showed that there were no significant differences between Dutch parents and parents with a non-Dutch background. However, these results can not be generalized when using the EMPATHIC questionnaire in other countries with other languages. Although its reliability and validity has been proven, thorough translation of the instrument is needed to provide evidence that the meaning of the translated statements is equivalent to the original statements [19
]. For this translation process, a framework has been described of 10 consecutive steps, based on a review of 12 guidelines for translation and cultural adaptation, to ensure principles of good practice [20
Only two validated parent satisfaction instruments have been documented in the literature for PICU settings [8
]. The instrument developed in the UK assessed the face and content validity although no reliability testing was performed [8
]. Despite the proper testing of the reliability and validity of the 23-item instrument developed in the USA, the authors stated that a limitation of this instrument is its restricted number of items [9
]. The authors stated that their instrument was not intended to be ‘all-inclusive’ but that it was rather directed to PICU care only. However, it is debatable whether 23 statements are sufficient to reflect PICU services. In contrast, after its validation process the EMPATHIC questionnaire included 65 statements. In this perspective, two issues are important to address: the number of statements needed to measure the complexity of PICU services and the length of the questionnaire related to the response rates. The latter is addressed in a review of 210 patient satisfaction studies. In 125 studies the number of items used in the survey was reported and ranged from 1 to 361 items [21
]. Of these, there was a weak negative correlation between the number of items and the response rate. A similar effect occurred between the Picker Patient Experience (PPE-15) questionnaire embedded in a four-page survey with 31 questions including demographic details and a 12-page survey with 108 questions [22
]. The analyses revealed that the length of the questionnaire did not lead to reduced response rates and there was no effect on the quality of data in terms of percentages of items completed. Therefore, the 65-statement EMPATHIC questionnaire seems feasible as it resulted in response rates of 63 and 56% in the two measurement periods. Incidentally, these response rates can be considered acceptable for satisfaction surveys because the mean initial response rate was 72.1% (SD = 19.8) in 124 satisfaction studies [21
]. The other issue to be addressed is the question of how many statements are needed to measure parent satisfaction for PICU services. Basically, an instrument should include items on all factors of importance to the trait under study. This refers to the content validity of an instrument. A review of ten satisfaction instruments designed for PICU, neonatal ICU, adult ICU, and pediatric wards documented a range of 15–45 items [12
]. The strength of the EMPATHIC questionnaire lies in the item generation and item selection phase where a large number of parents and healthcare professionals were consulted to identify the most important items [10
]. The items were converted into statements and theoretically conceptualized in domains related to family-centered care concepts [23
]. It is, therefore, recognized that the 65 statements of the EMPATHIC questionnaire reflect the most important issues of the PICU care.
Two limitations of the psychometric testing of the EMPATHIC questionnaire need to be addressed. The first concern is the test–retest reliability. This refers to administering the same instrument to the same respondents at two different moments in time to estimate its stability over time. A high correlation between the two measurement periods refers to a good test–retest reliability. It was decided not to burden the parents with two questionnaires in a short period of time. Therefore, as it was assumed that neither the care and the treatment nor the population of parents would change within 8 months, two cohorts of parents were included to test the stability of the findings over time.
The second limitation is the lack of criterion validity testing of the instrument. This validity refers to association of the results between the tested instrument and another validated instrument measuring the related concept. Although one parent satisfaction instrument for the PICU was tested to be valid [9
], its limitations to use it as the gold standard were based on a single center study, the limited items of the instrument, and the validity tested on a small group of 40 parents of which 27 responded. For that reason, congruent validity was chosen to examine part of the validity of the EMPATHIC questionnaire by testing the statements on four generally accepted gold standard questions measuring overall satisfaction.
Despite the recognition that satisfaction outcome measures are increasingly used as quality performance indicators [24
], the reality is that there is a paucity of PICU parent satisfaction instruments in the literature. However, it is expected that many PICUs have developed and carry out their own unit-based satisfaction survey. Therefore, and in conclusion, this study provides a reliable and valid parent satisfaction instrument that is feasible to administer to parents. The found empirical structure of the satisfaction-with-care statements can be considered adequate. The proven statistical evidence of the statements is of importance in order to be able to apply the EMPATHIC questionnaire in other PICUs. Nevertheless, including statements of clinical relevance specific to local PICU settings might be considered. Ultimately, using a validated instrument contributes to the empowerment of parents to work collaboratively with nurses and physicians on PICU quality of care.