Table 1.
Compliance (Proportion of Days Covered) | % | Persistence (60 day permissible gap) | |||
---|---|---|---|---|---|
No. days drug supplied (numerator) | No. days observed (denominator) | No. days in largest gap | No. days persistedc | ||
Truth (Figure 2A) | 120 | 180 | 66.7 | (46+7)=53 | 180 |
Claims data “raw” (Figure 2B) | |||||
ignoring days in hospital | 90 | 180 | 50.0 | (53+30)=83 | 67 |
subtract days in hospital (n=12)a | 90 | 168 | 53.5 | (83−12)=71 | 67 |
100% covered in hospital (n=12)b | 102 | 180 | 56.7 | 46 | 180 |
50% days supplied grace period (Figure 2C) | |||||
ignoring days in hospital | 112 | 180 | 62.0 | (46−15+7+30)=68 | 82 |
subtract days in hospital (n=12)a | 112 | 168 | 66.7 | (68−12)=56 | 180 |
100% covered in hospital (n=12)b | 124 | 180 | 68.9 | (46−15)=31 | 180 |
Proportion of days covered (PDC)=(number of days of drug supplied in the observation period/number of days in the observation period), capped at 1 or 100%.
PDC: corrected for immeasurable time in hospital by subtracting 12 days from denominator; persistence: subtract days in hospital (12 days) from gap length
PDC: corrected for immeasurable time in hospital by adding 12 days to numerator; persistence: subtract days in hospital (12 days) from gap length
defined by the number of days covered by drug before a gap of more than 60 days