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Table 9 Autocorrelation coefficient estimates (REML estimates of -1 and 1 are excluded, PW estimates < -1 are excluded)

From: Comparison of six statistical methods for interrupted time series studies: empirical evaluation of 190 published series

Statistical method Autocorrelation coefficient (ρ) estimate
All available datasets Series with ≥ 24 points Series with ≥ 100 points
N median (IQR) N median (IQR) N median (IQR)
ARIMA 189 0.04 (-0.15,0.30) 154 0.07 (-0.10,0.36) 31 0.19 (0.04,0.54)
PW 186 0.05 (-0.14,0.33) 155 0.07 (-0.10,0.38) 31 0.19 (0.04,0.54)
REML 175 0.20 (-0.01,0.54) 147 0.20 (-0.01,0.53) 31 0.23 (0.08,0.57)
Restricted to datasets where all methods can be compared
ARIMA 171 0.05 (-0.14,0.30) 147 0.06 (-0.11,0.35) 31 0.19 (0.04,0.54)
PW 171 0.05 (-0.14,0.31) 147 0.07 (-0.11,0.35) 31 0.19 (0.04,0.54)
REML 171 0.20 (-0.01,0.54) 147 0.20 (-0.01,0.53) 31 0.23 (0.08,0.57)