Validation of self-reported human papillomavirus vaccination in young adult men who have sex with men

Figures & data

Figure 1. Age cohort for the human papillomavirus vaccination programme for male individuals in Victoria, Australia.

Figure 2. Flow chart of study participant selection.

Table 1. Confusion matrix and corresponding likelihood ratios comparing self-reported vaccination status using computer-assisted self-interviewing with electronic health records among 1,665 GBMSM attending the Melbourne Sexual Health Centre.

	Electronic health records
Self-reported vaccination status	Vaccinated	Unvaccinated	Total	Likelihood ratio (95% CI)
Yes	661	151	812	2.4 (2.1 to 2.7)
No	75	214	289	0.19 (0.15 to 0.24)
Unsure	343	221	564	0.84 (0.74 to 0.97)
Total	1079	586	1665

Table 2. Sensitivity, specificity, predictive values and likelihood ratios of self-reported HPV vaccination status among GBMSM using electronic health records as the reference standard.

Parameters	All men (N=1665), Measure (95% CI)	All men excluding those who were unsure about their vaccination status (N=1101), Measure (95% CI)
Sensitivity	61.3% (58.3 to 64.2%)	89.8% (88.0 to 91.6%)
Specificity	74.2% (70.5 to 77.7%)	58.6% (55.7 to 61.5%)
Positive predictive value	81.4% (78.6 to 84.0%)	81.4% (79.1 to 83.7%)
Negative predictive value	51.0% (47.6 to 54.4%)	74.1% (71.5 to 76.6%)
Positive likelihood ratio	2.4 (2.1 to 2.7)	2.2 (1.9 to 2.5)
Negative likelihood ratio	0.52 (0.48 to 0.57)	0.17 (0.14 to 0.22)
Kappa coefficient	0.32 (0.28 to 0.36)	0.51 (0.46 to 0.57)
Accuracy	52.6% (50.1 to 55.0%)	79.5% (77.0 to 81.8%)

CI: Confidence intervals.

Table 3. Sensitivity and specificity of self-reported HPV vaccination status using computer-assisted self-interviewing compared to electronic health records among 1,665 GBMSM, stratified by different characteristics.

	Electronic health records		Self-reported vaccination status			Sensitivity	Specificity
Characteristics	Vaccinated	Unvaccinated	Yes	No	Unsure	Measure (95% CI)	Measure (95% CI)
Overall	1079	586	661	75	343	61.3% (58.3 to 64.2%)	74.2% (70.5 to 77.7%)
Age group
23–26	518	247	324	29	165	62.5% (59.1 to 66.0%)	70.5% (67.2 to 73.7%)
27–30	561	339	337	46	178	60.1% (56.9 to 63.3%)	77.0% (74.2 to 79.7%)
Residency
Australian-born citizens	535	296	328	25	182	61.3% (58.0 to 64.6%)	71.6% (68.6 to 74.7%)
Overseas-born residents^a	277	130	164	23	90	59.2% (54.4 to 64.0%)	74.6% (70.4 to 78.8%)
Overseas-born recent arrivals^b	246	151	153	27	66	62.2% (57.4 to 67.0%)	78.8% (74.8 to 82.8%)
Time since the last documented HPV vaccine dose
<1 year ago	217	586	130	23	64	59.9% (53.6 to 66.5%)	74.2% (71.2 to 77.3%)
1 year ago	425	586	257	25	143	60.5% (55.6 to 65.1%)	74.2% (71.5 to 76.9%)
≥2 years ago	437	586	274	27	136	62.7% (58.0 to 67.2%)	74.2% (71.6 to 76.9%)
Documented the number of HPV vaccine doses
One	203	586	84	32	87	41.4% (34.5 to 48.5%)	74.2% (71.2 to 77.3%)
Two	192	586	94	14	84	49.0% (41.7 to 56.3%)	74.2% (71.2 to 77.3%)
Three	684	586	483	29	172	70.6% (68.1 to 73.1%)	74.2% (71.8 to 76.6%)
HIV status & PrEP use
HIV-negative	630	395	359	56	215	57.0% (54.0 to 60.0%)	79.2% (76.8 to 81.7%)
PrEP users	390	167	273	16	101	70.0% (66.2 to 73.8%)	64.1% (60.1 to 68.1%)
People living with HIV	59	24	29	3	27	49.2% (38.4 to 59.9%)	62.5% (52.1 to 72.9%)
Number of male partners in the last 12 months
≤5	620	359	366	52	202	59.0% (55.9 to 62.1%)	80.8% (78.3 to 83.3%)
>5	459	227	295	23	141	64.3% (60.7 to 67.9%)	63.9% (60.3 to 67.5%)

^aOverseas born individuals who have resided in Australia for more than four years.

^bOverseas born individuals who have resided in Australia for less than four years.

Data availability statement

All data analyzed during this study are included in this article.