Parent verbal contingencies during the Lidcombe Program: Observations and statistical modeling of the treatment process

Purpose: The purpose of this study was to document parent presentation of the Lidcombe Program verbal contingencies and model potential relationships between contingency provision and treatment duration. 

Methods: Forty parent-child pairs undertaking the Lidcombe Program participated, 26 of whom completed Stage 1. All participants were included in the analyses. Parents completed weekly audio-recordings of treatment during practice sessions and a diary of treatment during natural conversations. The number and types of contingencies provided during practice sessions were counted for 520 recordings. Accelerated failure time modeling was used to investigate associations between contingency provision during the first 4 weeks of treatment and duration of time to complete Stage 1. 

Results: During practice sessions 91% of contingencies were for stutter-free speech, 6.8% were for stuttering and 2.7% were incorrectly applied. Parents often combined several verbal contingencies into one. During natural conversations, the number of verbal contingencies reportedly provided across the day was low, an average of 8.5 (SD = 7.82) contingencies for stutter-free speech and 1.7 (SD = 2.43) for unambiguous stuttering. There was a positive, significant relationship between the number of verbal contingencies for stuttering provided during the first 4 weeks of treatment and time taken to complete Stage 1.

Conclusion: Parents mostly provided the expected types of contingencies but the number was lower than expected. An unexpected association was found between number of verbal contingencies for stuttering and treatment duration. Further research is required to explore the relation between rates of parent verbal contingencies, treatment process duration, and treatment outcome.