Table 2. Subgroup analysis of HIV prevalence in older adults in China.

Subgroup	Number of studies	Sample size	Number of cases	Prevalence (%)	95% CI	I2 (% with P-value)
1. Sexual orientation: MSM population	5	1,720	178	11.8	8.5–15	59.24 (<0.05)
Not specified	41	361,679	5,560	2.0	1.8–2.2	99.4 (<0.001)
2. Sex: Male predominance (≥60%)	32	76,284	5,159	4.1	2.8–5.4	99.2 (<0.001)
No predominance	4	7,711	204	1.7	0.4–3.9	98.6 (<0.001)
3. Study site: Hospital	14	93,569	4,587	7.5	4.5–10.4	99.8 (<0.001)
Community	32	269,830	1,151	1.5	1.3–1.8	97.4 (<0.001)
4. Route of transmission: Commercial sex	12	28,404	610	2.2	1.8–2.6	71.3 (<0.001)
Not specified	33	334,785	5,110	2.0	1.8–2.2	99.5 (<0.001)
5. Education: Primary school and below (≥60%)	13	38,784	4,130	3.4	0.6–6.1	99.7 (<0.001)
Above primary school (≥60%)	8	7,167	205	3.9	2.1–5.8	96.8 (<0.001)
6. Occupation: Farmer predominance (≥60%)	11	9,586	283	2.6	1.7–3.5	90.2 (<0.001)
No predominance	4	3,149	246	6.9	0.2–11.5	97.0 (<0.001)
7. Economic Region: West	26	64,162	5,152	6.0	4.2–7.9	99.3 (<0.001)
Middle	5	59, 324	46	0.5	0.0–1.0	87.1 (<0.001)
East	15	239,913	540	1.0	0.7–1.3	97.5 (<0.001)
8. Area: Rural	5	4, 857	195	4.8	2.6–7.1	98.6 (<0.001)
Urban	12	21,194	732	5.8	4.3–7.3	97.2 (<0.001)
Urban and Rural	18	58,304	4,630	3.8	1.8–5.7	99.5 (<0.001)
9. Defined age for older adults (years): ≥50	41	357,402	5,654	2.4	2.2–2.5	99.4 (<0.001)
≥60	5	5,997	84	1.4	0.6–2.3	95.4 (<0.001)
10. Publication yeara: In or before 2014	15	22,8142	305	2.1	1.5–2.7	95.4 (<0.001)
After 2014	31	135,257	5,433	3.6	3.1–4.1	99.5 (<0.001)

Notes.

^aAnalyzed using a median splitting method.