Convergent validity of pain measuring tools among Nigerian children.

This prospective study was carried out at the Children Outpatient Clinic of the University College Hospital (UCH), Ibadan, Nigeria. The study aims to determine the convergent validity of the Oucher, Observer Pain Scale, Visual Analogue Scale (VAS) and the Numeric Rating Scale (NRS) among Nigerian children. Children aged between 6 months and 12 years who required venepuncture or phlebotomy for various investigative procedures were recruited. Demographic data and pain assessment scores were documented on a data collection form. Pain was assessed by a trained research assistant at baseline, during the procedure and immediately after the procedure using the 4 pain scales. The mean age (+/- SD) of the children was 5.5 +/- 4.3 years, boys accounted for 93 (52%) and girls 86 (48%). Pain score ranged from 0 (no pain) to 10 (worst pain) during the procedure; 72% (125) of the children had a pain score of at least 4. The median pain score during the procedure were 4 (Observer Pain Scale), 5 (Oucher) and 4 (VAS and NRS).The average measure intra-class correlation coefficient (ICC) showed that the Oucher, the VAS and the NRS pain scales are reliable pain measuring tools with an ICC of 0.63-0.69 at baseline and 0.72 - 0.73 during the procedure. The VAS, NRS and Oucher pain scales are valid pain tools that can be used to assess pain in Nigerian children.