Percent Agreement

Authors

Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

What percentage of the time 2 different readings of the same thing give you the same result

Calculation

Percent agreement equation¹ $$\text{Percent Agreement}=\frac{{\sigma }_s^2}{{\sigma }_s^2+{\sigma }_e^2}=\frac{\text{Number of concordant responses}}{\text{Total number of responses}}\times 100\mathrm{\%}$$

Scoring

Values range from 0.00 (not reliable) to 1.00 (perfectly reliable)

“Rule of thumb” Quick interpretation of reliability

Score	Reliability
0.00 – 0.20	Poor
0.21 – 0.40	Fair
0.41 – 0.60	Moderate
0.61 – 0.80	Good
0.81 – 1.00	Excellent

References

1.

Gisev N, Bell JS, Chen TF. Interrater agreement and interrater reliability: Key concepts, approaches, and applications. Research in social & administrative pharmacy: RSAP. 2013;9(3):330-338. doi:10.1016/j.sapharm.2012.04.004