Predictive validity of the Hand Assessment for Infants in infants at risk of unilateral cerebral palsy

Aim To evaluate the sensitivity, specificity, and predictive value of the Hand Assessment for Infants (HAI) in identifying infants at risk of being diagnosed with unilateral cerebral palsy (CP), and to determine cut-off values for this purpose. Method A convenience sample of 203 infants (106 females, 97 males) was assessed by the HAI at 3, 6, 9, and 12 months. Sensitivity, specificity, predictive values, and likelihood ratios were calculated using receiver operating characteristic curve analysis. Cut-off values were derived for different ages. The clinical outcome (unilateral CP yes/no) at 24 months or more served as an external criterion to investigate the predictive validity of HAI. Results Half of the infants developed unilateral CP. The area under the curve ranged from 0.77 (95% CI [confidence interval] 0.63-0.91) to 0.95 (95% CI 0.90-1.00) across HAI scales and age intervals. Likewise, sensitivity ranged from 63% to 93%, specificity from 62% to 91%, and accuracy from 73% to 94%. Interpretation HAI scores demonstrated overall accuracy that ranged from very good to excellent in predicting unilateral CP in infants at risk aged between 3.5 and 12 months. This accuracy increased with age at assessment and the earliest possible prediction was at 3.5 months of age, when appropriate HAI cut-off values for different ages were applied.