Table 5. Frequency and duration of pain.

Attribute	EHR Data Patients	CHT Data Patients	p-Value EHR vs CHT	Congruence EHR and CHT Data Patients (%)
2 or More Episodes of pain in prior 24h	53	123	< 0.001	28 (22.7)
Less than 2 Episodes of Pain in prior 24h	106	102	NS	27 (26.5)
Constant Pain from Onset or Pain Became Constant	47	119	< 0.001	24 (20.1)

P-values are from a X² distribution table for one degree of freedom and X² calculated as in Methods. NS means not significant. The denominator for percent congruence was the number of patients identified by CHT data.