Do Pain Measurement Instruments Detect the Effect of Pain-Reducing Interventions in Neonates? A Systematic Review on Responsiveness.

The effectiveness of pain-reducing interventions in newborns can only be determined if pain measurement instruments are responsive; that is, able to detect a decrease in pain intensity after the pain-reducing intervention. This review assesses the methodologic quality of studies on this measurement property-the responsiveness. We searched the literature published until January 2018 for validation studies of pain measurement instruments focusing on responsiveness to pain-reducing treatment in neonates. The methodologic quality of the included studies was rated using the COnsensus-based Standards for the selection of health Measurement INstruments checklist. Nine studies were included involving 10 pain measurement instruments. These studies differed with respect to the population, setting and type of pain-reducing intervention. In all studies, pain scores were significantly lower after a pain-reducing intervention and the instrument used was therefore considered responsive. We rated 4 studies as having poor methodologic quality, 5 as fair quality, and none as good quality. In conclusion, the responsiveness was studied for only 10 of the 43 existing pain measurement instruments for the use in neonates. Because this is an important property of a pain instrument, more research on this topic is needed, with attention for blinding and formulating a specific hypothesis before start of data collection. PERSPECTIVE: This review focuses on the property of measurement instruments to detect changes in pain intensity after a pain-reducing intervention in neonates. We concluded that this property-the responsiveness-is under studied and that the methodologic quality of the included studies was low. Future high-quality validation studies should focus on responsiveness.