Table 3.
Results of cluster analysis: clusters with high and low rates
| Case definition | High rate clusters
|
Low rate clusters
|
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cluster type | No of observed cases | No of expected cases | LLR | Cluster RR | p Value | Cluster type | No of observed cases | No of expected cases | LLR | Cluster RR | p Value | |
| Sociodemographic characteristics | ||||||||||||
| Gender: male | Primary | 10 | 4.97 | 7.06 | 2.01 | 0.352 | Primary | 24 | 40.73 | 7.88 | 0.59 | 0.171 |
| Marital status: married/cohabitated | Primary | 201 | 166.56 | 15.36 | 1.21 | <0.001 | Primary | 167 | 202.88 | 15.08 | 0.82 | <0.001 |
| Employment: unemployed | Primary | 4 | 0.55 | 7.98 | 7.23 | 0.108 | Primary | 18 | 33.46 | 6.85 | 0.54 | 0.240 |
| Duration of living in Guangzhou: ≤1 year | Primary | 16 | 4.60 | 11.64 | 3.47 | 0.007 | Primary | 27 | 45.20 | 8.50 | 0.60 | 0.051 |
| Migrants: yes | Primary | 148 | 101.24 | 36.39 | 1.46 | <0.001 | Primary | 131 | 189.25 | 37.98 | 0.69 | <0.001 |
| Migrants: yes | Secondary | 49 | 34.51 | 8.55 | 1.42 | 0.10 | Secondary | 1 | 8.63 | 9.03 | 0.12 | 0.078 |
| College students: yes | Primary | 52 | 27.02 | 19.58 | 1.92 | <0.001 | Primary | 16 | 36.26 | 13.15 | 0.44 | <0.001 |
| Sexual orientation: not heterosexual | Primary | 5 | 0.41 | 9.57 | 12.06 | 0.051 | Primary | 0 | 4.02 | 4.40 | 0 | 0.610 |
| Risky sexual behaviours | ||||||||||||
| Consumption of alcohol/other drug before sex: yes | Primary | 4 | 0.26 | 9.82 | 15.62 | 0.010 | Primary | 0 | 5.99 | 7.28 | 0 | 0.038 |
| Anal intercourse: yes | Primary | 5 | 0.38 | 13.39 | 13.32 | <0.001 | Primary | 0 | 4.58 | 5.22 | 0 | 0.309 |
| Multiple sexual partnerships: yes | Primary | 3 | 0.55 | 5.15 | 5.47 | 0.680 | Primary | 5 | 17.93 | 9.29 | 0.28 | 0.025 |
| Lived with one of multiple sex partners: no | Primary | 9 | 5.77 | 4.41 | 1.56 | 0.269 | Primary | 7 | 13.45 | 6.37 | 0.52 | 0.084 |
| Casual sex partners: yes | Primary | 4 | 0.51 | 6.93 | 7.88 | 0.296 | Primary | 1 | 10.45 | 9.07 | 0.09 | 0.012 |
| Unprotected sex: yes | Primary | 30 | 23.12 | 8.37 | 1.30 | 0.036 | Primary | 0 | 3.08 | 5.99 | 0 | 0.249 |
| STDs | ||||||||||||
| Self-reported STDs: yes | Primary | 2 | 0.13 | 5.52 | 15.46 | 0.630 | Primary | 0 | 3.49 | 3.75 | 0 | 0.960 |
All dichotomous, ordinal and nominal variables were scanned for high and low rate clusters by Bernoulli model, ordinal model and multinomial model, respectively. LLR, likelihood ratio; STDs, sexually transmitted diseases; RR, rate ratio.