Table 3.

Mean pulmonary artery pressure in patients compared with controls.

Age range	Mean  PAP ± SD		t-test	df	P value
	Sickle-cell patients	Controls
18–22	19.18 (9.79)	10.38 (6.99)	3.408	51	0.001*
23–27	24.42 (6.68)	7.09 (6.02)	5.325	28	0.001*
28–32	23.09 (7.07)	7.86 (4.61)	3.758	18	0.001*
33–44	23.05 (4.96)	10.09 (6.25)	1.121	8	0.295
Total	21.80 (8.77)	8.60 (2.99)	6.785	118	0.001*

* Statistically significant (2 sided), PAP = pulmonary artery pressure, and SD = standard deviation.