In signal amplification assays, the pooled sensitivity for CIN 2+ was lower in the group with the self-collected samples than in the clinician-collected sample group (77%; 95% confidence interval [CI], 69%-82% vs 93%; 95% CI, 89%-96%). The pooled specificity to exclude CIN 2+ was also lower in the group with the self-collected samples (84%; 95% CI, 77%-88% vs 86%; 95% CI, 81%-90%). In high-risk HPV assays based on PCR, there was no difference in sensitivity (96%) or specificity (79%) between the specimen groups.
With regard to the pooled relative sensitivity and specificity of signal amplification assays, those using self-swab samples were less sensitive and less specific for CIN 2+ (sensitivity ratio = 0.85; 95% CI, 0.80-0.89; specificity ratio = 0.96; 95% CI, 0.93-0.98) and CIN 3+ (sensitivity ratio = 0.86; 95% CI, 0.76-0.98; specificity ratio = 0.97; 95% CI, 0.95-0.99). Using PCR assays, there was no difference between groups in relative sensitivity for the diagnosis of CIN 2+ (sensitivity ratio = 0.99; 95% CI, 0.97-1.02) and CIN 3+ (sensitivity ratio = 0.99; 95% CI, 0.96-1.02). Relative specificity was slightly lower in the self-swab group for CIN 2+ (specificity ratio = 0.98; 95% CI, 0.97-0.99) and CIN 3+ (specificity ratio = 0.98; 95% CI, 0.97-0.99).
The second analysis to evaluate which outreach strategies are effective methods for screening underscreened/unscreened women found that delivering self-sample kits to patients was more effective than the control method, which was sending reminders to women to undergo conventional screening (95% vs 53%; mean difference [MD], 41%; 95% CI, 3%-78%). Similarly, mailing kits to patients compared favorably to the control method (25% vs 12%; MD, 13%; 95% CI, 10%-15%).
WHAT’S NEW
Self-collected specimens can beas reliable as clinician-collected ones
This is the first study to provide robust evidence that high-risk HPV PCR-based assays using patient self-collected specimens are as sensitive at diagnosing CIN 2+ or 3+ as using clinician-collected samples.
CAVEATS
Balancing lower specificity with reaching underscreened populations
Patients with a positive HPV test result require additional testing. The success rates for this follow-up are not known and could be a barrier to accurate diagnoses because of accessibility and patient willingness to follow up with a pelvic exam. In addition, self-collection may be less specific than cytology and could increase colposcopy referrals that lead to negative findings and overtreatment.12 However, the increased acceptance of this screening method could make it an effective strategy to reach underscreened or reluctant patients.
Continue to: CHALLENGES TO IMPLEMENTATION
