Persistence on prostaglandin ocular hypotensive therapy: an assessment using medication possession and days covered on therapy

Table 5 Sensitivity/specificity of 90 days/persistence

	Any quantity fills		Single bottle gills of 2.5 mL
Method of imputing days supply	Sensitivity	Specificity	Sensitivity	Specificity
Medication possession
Unadjusted days supply	56%	63%	47%	79%
2.0-2.1 Variable Factor*	60%	60%	53%	77%
2.0 Constant Factor/45
Minimum^†	61%	60%	54%	77%
Days covered
Unadjusted days supply	53%	68%	43%	99%
2.0-2.1 Variable Factor*	67%	69%	61%	90%
2.0 Constant Factor/45
Minimum^†	70%	70%	65%	90%

*Imputed days supply is unadjusted days supply multiplied by 2.0 (latanoprost, travoprost) or 2.1 (bimatoprost).
^†Imputed days supply is unadjusted days supply multiplied by 2.0 (all prostaglandins), with a minimum imputed estimate of 45 days.

ISSN: 1471-2415