Table 1.

Ghana Randomized Air Pollution and Health Study (GRAPHS) participant characteristics.

Characteristic	All children ($N=\mathrm{1,144}$)	Open fire stove, control ($N=414$)	Improved biomass stove ($N=430$)	LPG stove ($N=300$)
Categorical variables [$N$ (%)]
Child sex
Male	584 (51.0)	199 (48.1)	238 (55.3)	147 (49.0)
Wealth index
Mean (SD)	3.02 (1.4)	3.06 (1.5)	3.13 (1.3)	2.81 (1.4)
By category:
1 (very poor)	221 (19.3)	87 (21.0)	57 (13.3)	77 (25.7)
2	236 (20.6)	87 (21.0)	93 (21.6)	56 (18.7)
3	220 (19.2)	58 (14.0)	103 (24)	59 (19.7)
4	230 (20.1)	77 (18.6)	91 (21.1)	62 (20.7)
5 (least poor)	237 (20.7)	105 (25.4)	86 (20.0)	46 (15.3)
Ethnicity
0	254 (22.2)	133 (32.1)	72 (16.7)	49 (16.3)
1	199 (17.4)	84 (20.3)	88 (20.5)	27 (9.0)
2	165 (14.4)	36 (8.7)	55 (12.8)	74 (24.7)
3	159 (13.9)	33 (8.0)	76 (17.7)	50 (16.7)
4	149 (13.0)	62 (15.0)	52 (12.1)	35 (11.7)
5	218 (19.1)	66 (15.9)	87 (20.2)	65 (21.7)
Breastfeeding duration (months) (missing data $N=3$)a
3	22 (1.9)	2 (0.5)	20 (4.7)	0 (0.0)
6	56 (4.9)	25 (6.0)	29 (6.7)	2 (0.7)
9	90 (7.9)	63 (15.2)	18 (4.2)	9 (3.0)
$\ge 12$	973 (85.0)	323 (78.0)	361 (84.0)	289 (96.3)
Pattern of available growth data (time points) (five time $\text{points}=0$, 3, 6, 9, and 12 months)
Five	880 (76.9)	306 (73.9)	320 (74.4)	254 (84.7)
Four	162 (14.2)	69 (16.7)	51 (11.9)	42 (14)
Three	76 (6.6)	35 (8.5)	37 (8.6)	4 (1.3)
Two	23 (2.0)	3 (0.7)	20 (4.7)	0 (0.0)
One	3 (0.3)	1 (0.2)	2 (0.5)	0 (0.0)
Continuous variables {ppm [median (IQR)]}
Maternal average prenatal CO exposureb	1.07 (0.65–1.65)	1.15 (0.71–1.76)	1.12 (0.68–1.60)	0.94 (0.53–1.50)
Child average postnatal CO exposureb	0.53 (0.24–1.02)	0.54 (0.28–1.13)	0.55 (0.24–1.01)	0.48 (0.21–0.91)
Maternal prenatal ${\mathrm{PM}}_{2.5}$ exposure (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)c	67.8 (43.2–96.4)	75.8 (47.3–101.1)	71.7 (48.6–101.5)	42 (29.2–65.9)
Maternal postnatal ${\mathrm{PM}}_{2.5}$ exposure (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)c	54.7 (38.7–79.5)	57.5 (39.5–88.8)	60.8 (41.8–79.6)	48.4 (33.6–58.4)
Maternal age at enrollment (y)	26.9 (22.3–33.6)	27.3 (21.8–33.7)	27.7 (23.3–34.2)	25.9 (21.8–32.2)
Maternal BMI at enrollment (${\mathrm{kg}/\mathrm{m}}^2$)	22.9 (21.1–25)	22.7 (21.1–25)	23.1 (21.4–25)	22.8 (20.9–24.8)
Gestational age at delivery (wk)	39.7 (38.9–40.6)	39.7 (38.9–40.6)	39.7 (38.9–40.7)	39.6 (38.9–40.4)

Note: BMI, body mass index; CO, carbon monoxide; IQR, interquartile range; LPG, liquified petroleum gas; ${\mathrm{PM}}_{2.5}$, fine particulate matter (PM with an aerodynamic diameter of $\le 2.5\mathrm{\mu }\mathrm{m}$); SD, standard deviation.

^a Breastfeeding assessed via questionnaire every 3 months over the infant’s first year of life.

^b Prenatal maternal and postnatal infant personal CO exposure measured in parts per million at four and three time points, respectively. Prenatal average CO exposures include pre-intervention and post-intervention exposure measurements. All children included in these analyses had prenatal and postnatal CO measurements ($N=\mathrm{1,144}$).

^c Prenatal and postnatal maternal personal ${\mathrm{PM}}_{2.5}$ exposure measured in micrograms per meter cubed, in those with paired prenatal and postnatal data (total $N=358$; by study arm: $\text{control}=165$, $\text{improved biomass}=118$, $\text{LPG}=75$). Of the $N=358$ prenatal assessments, 351 (92%) occurred after the stove intervention began. Prenatal ${\mathrm{PM}}_{2.5}$ was measured at the median gestational age of 22.7 wk (IQR: 18.4–26.9) and postnatal ${\mathrm{PM}}_{2.5}$ was measured at the median child age of 3.5 months (IQR: 2.7–5.2).