Table III.

HR data according to the severity of cocaine exposure (observed means and standard errors)

	No cocaine	Light cocaine	Heavy cocaine	P *
Sample size (n)
Birth	207	52	43
2–6 months	165	36	35
HR
Birth	130.31 (0.62)	132.47(1.23)	134.40(1.37)	0.015†
2–6 months	142.47(0.70)||	141.53 (1.50)||	145.10(1.53)||	0.208
RMSSD
Birth	21.65 (0.44)	21.11 (0.85)	19.37 (0.93)	0.048†
2–6 months	20.05 (0.35)||	23.43 (1.30)	20.43 (0.86)	0.017‡
SDNN
Birth	47.25 (0.84)	43.67 (1.66)	39.72 (1.51)	0.002†
2–6 months	48.48 (0.72)	51.24(2.14)||	48.57(1.83)||	0.456
HF
Birth	64.58 (3.61)	54.83 (5.99)	45.17(4.74)	0.013†
2–6 months	61.45 (3.35)	90.56(12.83)||	59.24(6.19)||	0.033‡
LF
Birth	150.76(6.89)	129.16(11.31)	116.12(14.04)	0.038†
2–6 months	140.15 (6.40)	170.32(18.44)	128.65(14.18)||	0.185
Total
Birth	1163.70 (57.85)	934.16(81.79)	803.04(87.31)	0.179
2–6 months	1160.84(80.98)	1309.84(135.16)	1134.03 (130.26)||	0.025§
VLF
Birth	288.87(16.00)	246.79 (27.28)	256.55 (46.60)	0.478
2–6 months	246.34 (35.85)||	206.32 (24.78)	211.79 (33.72)	0.407
ULF
Birth	659.33 (41.52)	530.26 (51.81)	406.40 (35.96)	0.187
2–6 months	713.60 (44.59)	847.93 (97.52)	734.29 (85.75)||	0.014§
SNN-50
Birth	5320.21 (319.81)	4738.43 (545.57)	3823.91 (600.47)	0.026†
2–6 months	4833.81 (324.20)	7579.70(1152.47)	5493.66 (782.17)||	0.022‡
SDNNI
Birth	30.92 (0.65)	29.25(1.28)	26.00(1.22)	0.015†
2–6 months	28.74 (0.49)||	30.35(1.21)	28.83 (1.22)||	0.425
SDANN
Birth	35.40 (0.83)	33.84(1.99)	29.53 (1.48)	0.043†
2–6 months	7.93 (0.79)	40.89 (2.56)||	37.37(1.54)||	0.180

Values presented as mean (SE) unless otherwise indicated.

^*P values are calculated from the repeated measures analyses adjusting for body surface area.

^†Heavy cocaine versus no cocaine at birth.

^‡Light cocaine versus no cocaine at 2 to 6 months.

^§No post-hoc pairwise differences were statistically significant at the adjusted alpha level of 0.017 ( = 0.05/3).

^||Significant change at 2 to 6 months of age from birth (P < .01).