Fig. 1

The contrasting distribution of PN visit attendance for participants in the PN (N = 266) and PN + CM (N = 271) treatment groups. Bars indicate the percentage of participants in the designated treatment group who achieved each total number of PN visits from 0 to 11 during a 6-month intervention. Incentives were available on an escalating scale starting at $10 and increasing to $30 per visit; PN + CM could earn a total of $220 for attending all visits