Table 5.

Agreement among methods of measuring onset

Correspondence across Informants (on prospective dimensional measures)
		Parent Rating
		Regression	No Regression
Examiner Rating	Regression	21	7
	No Regression	1	3
	κ (95% CI): 0.30 (−0.03 to 0.64)	Positive agreement: 84%	Negative agreement: 43%
	Percent agreement: 75%
Correspondence across Rating Types (on parent prospective measures)
		Dimensional Rating
		Regression	No Regression
Categorical Rating	Regression	12	3
	No Regression	10	7
	κ (95% CI): 0.21 (−0.10 to 0.51)	Positive agreement: 65%	Negative agreement: 52%
	Percent agreement: 59%
Correspondence across Timing (on parent categorical measures)
		Retrospective Rating1
		Regression	No Regression
Prospective Rating	Regression	7	8
	No Regression	2	14
	κ (95% CI): 0.35 (0.04 to 0.65)	Positive agreement: 58%	Negative agreement: 74%
	Percent agreement: 68%

¹Retrospective rating missing for 1 participant

Note:

Positive agreement is the proportional agreement in positive (“Regression”) ratings, calculated as:

$$\frac{2\ast \text{Number of }"\text{Regression}"\text{ ratings by both raters}}{\text{Number of }"\text{Regression}"\text{ ratings by rater }1+\text{Number of }"\text{Regression}"\text{ ratings by rater }2}$$

Negative agreement is the proportional agreement in negative (“No Regression”) ratings, calculated as:

$$\frac{2\ast \text{Number of }"\text{No Regression}"\text{ ratings by both raters}}{\text{Number of }"\text{No Regression}"\text{ ratings by rater }1+\text{Number of }"\text{No Regression}"\text{ ratings by rater }2}$$