Table 1.
Baseline characteristics of the participants.
| All Participants (n = 350) |
Being Followed Up at Month 12 (n = 274) |
Dropouts (n = 76) |
p Values | |
|---|---|---|---|---|
| n (%) | n (%) | n (%) | ||
| Socio-demographics | ||||
| Age group (years) | ||||
| 18–24 | 48 (13.7) | 34 (12.4) | 14 (18.4) | 0.34 |
| 25–30 | 128 (36.6) | 106 (38.7) | 22 (28.9) | |
| 31–40 | 133 (38.0) | 103 (37.6) | 30 (39.5) | |
| >40 | 41 (11.7) | 31 (11.3) | 10 (13.2) | |
| Relationship status | ||||
| Currently single | 265 (75.7) | 210 (76.6) | 55 (72.4) | 0.44 |
| Married or cohabited with a man | 85 (24.3) | 64 (23.4) | 21 (27.6) | |
| Highest education level attained | ||||
| Secondary or below | 47 (13.4) | 37 (13.5) | 10 (13.2) | 0.94 |
| Tertiary of above | 303 (86.6) | 237 (86.5) | 66 (86.8) | |
| Employment status | ||||
| Full-time | 290 (82.9) | 229 (83.6) | 61 (80.3) | 0.50 |
| Part-time/unemployed/retired/students | 60 (17.1) | 45 (16.4) | 15 (19.7) | |
| Monthly personal income, HK$ (US$) | ||||
| <10,000 (1282) | 37 (10.6) | 27 (9.9) | 10 (13.2) | 0.28 |
| 10,000–19,999 (1282–2564) | 106 (30.3) | 87 (31.8) | 19 (25.0) | |
| 20,000–39,999 (2565–5128) | 134 (38.3) | 107 (39.1) | 27 (35.5) | |
| 40,000 (5129) | 67 (19.1) | 50 (18.2) | 17 (22.4) | |
| Refuse to disclose | 6 (1.7) | 3 (1.1) | 3 (3.9) | |
| Sexual orientation | ||||
| Homosexual | 319 (91.1) | 252 (92.0) | 67 (88.2) | 0.30 |
| Bisexual | 31 (8.9) | 22 (8.0) | 9 (11.8) | |
| Lifestyles | ||||
| Smoking in lifetime | ||||
| No | 257 (73.4) | 203 (74.1) | 54 (71.1) | 0.60 |
| Yes | 93 (26.6) | 71 (25.9) | 22 (28.9) | |
| Drinking in the past year | ||||
| No | 86 (24.6) | 64 (23.4) | 22 (28.9) | 0.32 |
| Yes | 264 (75.4) | 210 (76.6) | 54 (71.1) | |
| History of HIV and other STIs and service utilization | ||||
| Self-reported HIV sero-status | ||||
| Negative | 311 (88.9) | 251 (91.6) | 60 (78.9) | 0.02 |
| Positive | 6 (1.7) | 4 (1.5) | 2 (2.6) | |
| Refuse to disclose | 11 (3.1) | 7 (2.6) | 4 (5.3) | |
| Had never tested for HIV antibody | 22 (6.3) | 12 (4.4) | 10 (13.2) | |
| History of HPV infection and/or genital warts (Yes) | 31 (8.9) | 27 (9.9) | 4 (5.3) | 0.21 |
| History of other STIs (Yes) | 59 (16.9) | 47 (17.2) | 12 (15.8) | 0.78 |
| Utilization of other HIV/STI prevention services (e.g., receiving free condoms, peer education and pamphlets, and attending seminars) (Yes) | 81 (23.1) | 69 (25.2) | 12 (15.8) | 0.09 |
| Sexual behaviors in the past six months | ||||
| Anal intercourse with regular male sex partners (Yes) | 293 (83.7) | 230 (83.9) | 63 (82.9) | 0.83 |
| Anal intercourse with non-regular male sex partners (Yes) | 170 (48.6) | 124 (45.3) | 46 (60.5) | 0.02 |
| Anal intercourse with male sex workers (Yes) | 9 (2.6) | 4 (1.5) | 5 (6.6) | 0.01 |
| Condomless anal intercourse with men (Yes) | 176 (50.3) | 142 (51.8) | 34 (44.7) | 0.27 |
| Multiple male sex partnerships (Yes) | 191 (54.6) | 143 (52.2) | 48 (63.2) | 0.09 |
| Sexual intercourse with female sex partners (Yes) | 6 (1.7) | 3 (1.1) | 3 (3.9) | 0.09 |
| Condomless sex with female sex partners (Yes) | 3 (0.9) | 2 (0.7) | 1 (1.3) | 0.62 |
| Sexualized drug use (use of psychoactive substances before or during sexual intercourse) (Yes) | 20 (5.7) | 17 (6.2) | 3 (3.9) | 0.45 |
| Knowledge related to HPV or HPV vaccination | ||||
| Both males and females could be affected by HPV | ||||
| Yes a | 335 (95.7) | 264 (96.4) | 71 (93.4) | 0.11 |
| No | 5 (1.4) | 2 (0.7) | 3 (3.9) | |
| Do not know | 10 (2.9) | 8 (2.9) | 2 (2.6) | |
| HPV infection could cause STI | ||||
| Yes a | 317 (90.6) | 248 (90.5) | 69 (90.8) | 0.79 |
| No | 8 (2.3) | 7 (2.6) | 1 (1.3) | |
| Do not know | 25 (7.1) | 19 (6.9) | 6 (7.9) | |
| HPV infection could cause cancers among males | ||||
| Yes a | 258 (73.7) | 200 (73.0) | 58 (76.3) | 0.54 |
| No | 27 (7.7) | 20 (7.3) | 7 (9.2) | |
| Do not know | 65 (18.6) | 54 (19.7) | 11 (14.5) | |
| HPV could be totally cured by available treatment | ||||
| Yes | 62 (17.7) | 48 (17.5) | 14 (18.4) | 0.93 |
| No a | 171 (48.9) | 133 (48.5) | 38 (50.0) | |
| Do not know | 117 (33.4) | 93 (33.9) | 24 (31.6) | |
| Availability of effective HPV vaccination for males in Hong Kong | ||||
| Yes a | 288 (82.3) | 229 (83.6) | 59 (77.6) | 0.12 |
| No | 8 (2.3) | 4 (1.5) | 4 (5.3) | |
| Do not know | 54 (15.4) | 41 (15.0) | 13 (17.1) | |
| Number of shots required to prevent HPV infection in males | ||||
| 3 a | 176 (50.3) | 135 (49.3) | 41 (53.9) | |
| Other answers/Do not know | 174 (49.7) | 139 (50.7) | 35 (46.1) | |
| Number of correct responses, mean (SD) | 4.4 (1.3) | 4.4 (1.3) | 4.4 (1.2) | 0.91 |
| Perceptions related to HPV or HPV vaccination based on the HBM | ||||
| Perceived susceptibility to HPV (high/very high) | ||||
| Perceived risk of contracting HPV in lifetime | 89 (25.4) | 65 (23.7) | 24 (31.6) | 0.16 |
| Perceived risk of contracting genital warts in lifetime | 72 (20.6) | 50 (18.2) | 22 (28.9) | 0.04 |
| Perceived risk of having penile/anal cancers in lifetime | 42 (12.0) | 32 (11.7) | 10 (13.2) | 0.73 |
| Perceived Susceptibility Scale b, mean (SD) | 8.2 (2.6) | 8.1 (2.6) | 8.8 (2.7) | 0.35 |
| Perceived severity of HPV-related diseases (agree/strongly agree) | ||||
| HPV infection would increase risk of HIV acquisition | 106 (30.3) | 81 (29.6) | 25 (32.9) | 0.58 |
| HPV infection would cause penile or anal cancers | 127 (36.3) | 98 (35.8) | 29 (38.2) | 0.70 |
| Genital warts would have severe harms on your health | 182 (52.0) | 140 (51.1) | 42 (55.3) | 0.52 |
| Penile or anal cancers would have severe harms on your health | 263 (75.1) | 207 (75.5) | 56 (73.7) | 0.74 |
| Perceived Severity Scale c, mean (SD) | 13.4 (3.1) | 13.3 (3.2) | 13.8 (2.7) | 0.43 |
| Perceived benefits of HPV vaccination (agree/strongly agree) | ||||
| HPV vaccination is highly effective in preventing HPV infection | 273 (78.0) | 210 (76.6) | 63 (82.9) | 0.24 |
| HPV vaccination is highly effective in preventing genital warts | 240 (68.6) | 181 (66.1) | 59 (77.6) | 0.054 |
| HPV vaccination is highly effective in preventing penile/anal cancers | 214 (61.1) | 166 (60.6) | 48 (63.2) | 0.68 |
| HPV vaccination can protect you for a long time | 193 (55.1) | 149 (54.4) | 44 (57.9) | 0.59 |
| Perceived Benefit Scale d, mean (SD) | 15.3 (2.5) | 15.2 (2.6) | 15.6 (2.1) | 0.20 |
| Perceived barriers of receiving HPV vaccination (agree/strongly agree) | ||||
| It is not worthy speeding HK$6000–7000 (US$774–903) to receive HPV vaccination | 107 (30.6) | 88 (32.1) | 19 (25.0) | 0.23 |
| You would have severe side-effects after receiving HPV vaccination | 37 (10.6) | 30 (10.9) | 7 (9.2) | 0.66 |
| Others would think you are having high-risk behaviors if you receive HPV vaccination | 45 (12.9) | 37 (13.5) | 8 (10.5) | 0.49 |
| You would be stigmatized when you receive HPV vaccination | 34 (9.7) | 26 (9.5) | 8 (10.5) | 0.79 |
| If you already infected with HPV, HPV vaccination could not protect you | 111 (31.7) | 88 (32.1) | 23 (30.3) | 0.76 |
| Perceived Barrier Scale e, mean (SD) | 12.4 (3.1) | 12.4 (3.1) | 12.2 (3.5) | 0.76 |
| Perceived cue to action related to HPV vaccination (agree/strongly agree) | ||||
| Mass media suggest males to receive HPV vaccination | 62 (17.7) | 46 (16.8) | 16 (21.1) | 0.39 |
| People who are important to you would suggest you to receive HPV vaccination | 83 (23.7) | 66 (24.1) | 17 (22.4) | 0.76 |
| Cue to Action Scale f, mean (SD) | 4.9 (2.0) | 4.8 (2.0) | 5.2 (2.0) | 0.14 |
| Perceived self-efficacy related to HPV vaccination (agree/strongly agree) | ||||
| You are confident to receive HPV vaccination in the next year if you want | 160 (45.7) | 129 (47.1) | 31 (40.8) | 0.33 |
| Receiving HPV vaccination in the next year is easy for you if you want | 182 (52.0) | 148 (54.0) | 34 (44.7) | 0.15 |
| Perceived Self-efficacy Scale g, mean (SD) | 6.8 (2.0) | 6.9 (2.0) | 6.7 (2.0) | 0.37 |
| Behavioral intention to take up HPV vaccination (likely/very likely) | ||||
| Likelihood of taking up three required doses of HPV vaccines in the next year | 64 (18.3) | 52 (19.0) | 12 (15.8) | 0.53 |
a Correct response. b Perceived Susceptibility Scale: three items, Cronbach’s alpha: 0.85, one factor was identified by exploratory factor analysis, explaining for 77.2% of total variances. c Perceived Severity Scale: four items, Cronbach’s alpha: 0.72, one factor was identified by exploratory factor analysis, explaining for 54.9% of total variances. d Perceived Benefit Scale: four items, Cronbach’s alpha: 0.79, one factor was identified by exploratory factor analysis, explaining for 62.4% of total variances. e Perceived Barrier Scale: five items, Cronbach’s alpha: 0.62, one factor was identified by exploratory factor analysis, explaining for 57.9% of total variances. f Cue to Action Scale: two items, Cronbach’s alpha: 0.61, one factor was identified by exploratory factor analysis, explaining for 56.2% of total variances. g Perceived Benefit Scale: two items, Cronbach’s alpha: 0.79, one factor was identified by exploratory factor analysis, explaining for 82.5% of total variances. HK: Hong Kong; HIV: human immunodeficiency virus; STI: sexually transmitted infection; and HPV: human papillomavirus.