Table 1: The characteristics of studies including in this meta-analysis.

First authorM/F ratioDiagnostic age (month)*Duration of exposure (month)*Diameter of calculi (mm)Percent of asymptomatic patients (%)Patient typesTreatment typesSample sizeFollow-up duration (month)Quality score
1361224

Sun [22]2.13 : 111.8, 6–369.5, 0.5–24—, —0IPST, CT221520228
Chen [20]1.88 : 124.0, 2–9617.0, 2–69—, —87.8OPNO49308
Wen [15]3.17 : 123.4, 2–8412.4, —<10, 100.0%38.0IPCT50329
Wen [14]2.61 : 125.5, 16–56—, ——, —0IPST, CT1951947
Zhang [19]0.67 : 116.0, 1–1615.7, —<5, 100.0%OPCT54497
Shen [16]—, ——, ——, —93.6OPDW2651391782342537
Yang [21]3.00 : 118.0, 9–3311.1, 5–18—, —0IPCT8610
Sun [23]1.47 : 1 13.5, — 12.5, — —, 94.9% 65.8IPCT292010
OPCT5046
Kuang [32] and Gao [38]1.82 : 119.0, 1–3610.8, 1–191–72, 89.6%73.3IPCT966675/91$7
Liu [17]1.61 : 119.8, 6–3616.5, 2–361–9, 100.0%91.5OPCT47428
Chang [33]1.24 : 1—, ——, ——, —OPDW431521366
Zhang [28]2.64 : 1 14.0, 2–36 —, — 5–15, 97.5% 68.8IPCT37308
IPST4341
Wang [30]1.47 : 111.2, 2–66—, ——, —99.4OPCT3892953067
Sun [25]0.81 : 114.0, 2–9611.0, 2–29—, 76.9%92.3IPCT65469
Tang [24]1.68 : 1 —, 2–120 —, — 2–13, —OPCT44307
OPDW3014
Zhang [39]—, ——, —>4, — OPCT4176
Zhu [34]2.15 : 115.6, 3–36—, —4–10, 100.0%IP, OPNO75595
Zhu [27]0.77 : 19.2#, 2–66—, —3–20, —98.2OPCT2867
He [26]0.67 : 118.0, 5–36—, 1–18<5, 100.0%73.3OPCT60549
Shang [36]1.70 : 1 26.0, 13–48 —, — —, 67.9%IPST27258
IPCT5451
Zhang [37]1.78 : 116.0, 2–3615.0, 2–36—, —IPST, CT9861/9878/9086/918
Mi [35]2.00 : 144.4, 1–72—, ——, 95.0%OPCT15137
Long [31]0.68 : 137.0, 19–7214.0, 2–324–11, —IP, OPCT37348
Wang [29]1.54 : 120.0, 3–36—, —4–19, —80.3IP, OPCT127941111138
Xu [18]1.55 : 120.4, 1–60—, 1–36—, 100.0%OPDW86869

M: male; F: female; IP: inpatient; OP: outpatient; ST: surgical treatment; CT: conservative treatment; DW: only drinking more water; NO: no description.
*The data was expressed as mean and range.
#The value was the median; in order to facilitate the calculation, we treated it as mean.
The study [38] followed up the patients at 18 months after treatment initiation.