Table 3.
Subgroup Analysis of Study-Level Factors on the Risk of Local Adverse Events.
| Study-Level Factor | No. studies | RR | 95% CI | P-value |
|---|---|---|---|---|
| No. injections | 0.11 | |||
| 1-2 | 7 | 1.26 | 1.00-1.61 | |
| 3 | 10 | 1.09 | 0.92-1.28 | |
| >3 | 8 | 1.55 | 1.16-2.07 | |
| Follow-up duration | 0.12 | |||
| 1-3 mo | 7 | 1.65 | 1.20-2.28 | |
| 4-6 mo | 14 | 1.14 | 0.99-1.31 | |
| >6 mo | 4 | 1.19 | 0.77-1.84 | |
| Sample size | 0.33 | |||
| ≥100 per group | 13 | 1.17 | 1.02-1.34 | |
| <100 per group | 12 | 1.38 | 1.03-1.85 | |
| Publication year | 0.37 | |||
| Before 2000 | 7 | 1.48 | 1.07-2.04 | |
| 2000-2009 | 12 | 1.14 | 0.98-1.34 | |
| After 2009 | 6 | 1.23 | 0.95-1.60 | |
| Outcome assessor blinding | 0.41 | |||
| No | 4 | 1.12 | 0.91-1.39 | |
| Yes | 21 | 1.25 | 1.08-1.46 | |
| Molecular weight (kDa) | 0.43 | |||
| ≥6,000 | 7 | 1.28 | 1.00-1.64 | |
| >1,500 to <6,000 | 6 | 1.00 | 0.73-1.37 | |
| ≤1,500 | 9 | 1.24 | 1.05-1.46 | |
| Patient blinding | 0.52 | |||
| No | 1 | 1.57 | 0.70-3.55 | |
| Yes | 24 | 1.20 | 1.06-1.36 | |
| Cross-linked | 0.60 | |||
| Yes | 10 | 1.29 | 1.03-1.60 | |
| No | 13 | 1.20 | 1.03-1.40 | |
| Industry-funded study | 0.66 | |||
| No | 5 | 1.30 | 0.91-1.87 | |
| Yes | 20 | 1.19 | 1.05-1.36 | |
| HA origin | 0.77 | |||
| Bacterial | 10 | 1.23 | 0.99-1.53 | |
| Avian | 14 | 1.20 | 1.03-1.39 | |
| US approved HA | 0.84 | |||
| Yes | 21 | 1.21 | 1.06-1.39 | |
| No | 4 | 1.17 | 0.85-1.61 | |
| Injector blinding | 0.98 | |||
| No | 21 | 1.21 | 1.06-1.37 | |
| Yes | 4 | 1.20 | 0.58-2.46 |
HA = hyaluronic acid; RR = risk ratio; US = United States.