Table 4.

Results of meta-regression and subgroup analysis concerning the frequency of pheochromocytoma and/or paraganglioma (PPGL) among patients with von Hippel–Lindau disease (vHL) type 2B.

	Meta-regression				Subgroup analysis
	N studies	N vHL	OR (95% CI)	P value	Frequency (%, 95% CI)	Cochran P value	I²
Publication year	24	256	1.00 (0.95–1.05)	0.965	–a	–a	–a
Sample size	24	256	1.00 (0.96–1.04)	0.975	–a	–a	–a
Region	24	256	–	0.138b	–a	–a	–a
Europe	7	83	–c	–c	37.8 (27.8–48.9)	0.778	0%
Asia and Pacific	11	105	1.97 (0.85–4.57)	0.112	55.0 (39.3–70.0)	0.066	45.2%
America	6	68	2.55 (0.91–7.12)	0.074	58.8 (30.4–82.4)	0.052	58.0%
Sampling method	24	256	–	0.361b
Consecutive	4	62	–c	–c	45.6 (24.0–69.0)	0.094	59.1%
Convenience	15	155	1.48 (0.58–3.80)	0.412	55.9 (46.1–65.2)	0.135	12.7%
Not specified	5	39	0.72 (0.21–2.51)	0.606	40.8 (17.2–69.4)	0.118	47.7%
Diagnosis	24	256	–	0.301b
Included genetic testing/not specified	20	222	–c	–c	46.2 (35.8–56.9)	0.021	44.4%
Clinical criteria only	4	34	2.04 (0.70–5.92)	0.301	73.5 (45.7–90.0)	0.272	29.6%

^aNot performed, as this is a continuous variable; ^bOmnibus P  value for this variable; ^cReference category.