Table 2

Meta-analytic results of HRV in patients compared to controls across psychiatric subgroups and current medication use

Category	No. of effect sizes, k	No. of patients	No. of controls	Hedges g (95% CI)	Q	Heterogeneity p value	Egger regression p value^*	Fail-safe N^*	Sensitivity analysis, range^†
Overall	151	6226	6426	−0.582 (−0.663 to −0.501)^§	645.563	< 0.001	< 0.001	8069	−0.589 to −0.556
Disorder subgroups
Anxiety	47	1365	1469	−0.360 (−0.505 to −0.215)^§	35.358	< 0.001	0.70	872	−0.379 to −0.331
Mood	52	2838	2882	−0.462 (−0.593 to −0.331)^§			0.020	2712	−0.471 to −0.439
Psychotic	41	1713	1660	−0.952 (−1.105 to −0.800)^§			< 0.001	4978	−1.011 to −0.886
Substance dependence	11	310	415	−0.694 (−0.982 to −0.405)^§			0.011	193	−0.716 to −0.630
Medication use^‡	142	5994	6163	−0.581 (−0.662 to −0.500)^§			< 0.001	5333	−0.590 to −0.555
Not medicated	82	3755	4343	−0.471 (−0.577 to −0.365)^§	9.893	0.002	0.009	5980	−0.479 to −0.440
Medicated	60	2239	1820	−0.734 (−0.859 to −0.609)^§			0.15	6624	−0.759 to −0.675
Anxiety disorders	44	1319	1439	−0.330 (−0.474 to −0.186)^§			0.37	678	−0.350 to −0.300
Not medicated	30	844	1035	−0.334 (−0.510 to −0.158)^¶	0.008	0.93	0.57	299	−0.363 to −0.288
Medicated	14	475	404	−0.321 (−0.571 to −0.071)^**			0.38	63	−0.385 to −0.300
Mood disorders	49	2739	2784	−0.470 (−0.560 to −0.380)^§			0.014	2607	−0.488 to −0.454
Not medicated	29	2008	2182	−0.360 (−0.472 to −0.249)^§	10.332	0.001	0.41	628	−0.395 to −0.328
Medicated	20	731	602	−0.668 (−0.818 to −0.517)^§			0.31	651	−0.710 to −0.641
Psychotic disorders	40	1692	1639	−0.983 (−1.196 to −0.770)^§			< 0.001	4765	−1.013 to −0.885
Not medicated	19	812	987	−0.901 (−1.210 to −0.592)^§	0.515	0.47	< 0.001	869	−0.939 to −0.735
Medicated	21	880	652	−1.058 (−1.353 to −0.763)^§			0.24	1541	−1.120 to −0.888
Substance dependence disorders	9	244	301	−0.694 (−0.897 to −0.491)^§			0.038	133	−0.744 to −0.649
Not medicated	4	91	139	−0.592 (−0.907 to −0.277)^¶	0.684	0.41	0.16	15	−0.731 to −0.465
Medicated	5	153	162	−0.766 (−1.032 to −0.501)^§			0.006	53	−0.906 to −0.686

CI = confidence interval; HRV = heart rate variability.
↵* Tests of publication bias conducted for the overall group of studies as well as for subgroups, p value 2-tailed.
↵† Sensitivity analyses conducted using 1 study removed.
↵‡ Current medication use not stated in 9 studies, which were thus were removed from medication subgroup analyses. “Not medicated” indicates patients who were either medication-free or medication-naive at time of physiological testing.
↵§ p < 0.0001, 2-tailed.
↵¶ p < 0.001, 2-tailed.
↵** p < 0.01, 2-tailed.