Lützen TH, et al.— This study was designed to examine the association between psychiatric conditions, general practitioner (GP) attendance, and indicators of psychological symptoms prior to human papilloma virus (HPV) vaccination and the risk of referral to an HPV center following vaccination. Researchers found that women who were referred to HPV centers because of suspected adverse events after vaccination more often had preexisting psychiatric conditions, psychological symptoms, or frequent GP attendance prior to HPV vaccination.

Methods:

• This trial was a register-based, matched case–control study.
• Cases were identified from five Danish, regional HPV centers.
• Health data for cases and controls were obtained from national registries.
• Cases were defined as women referred to an HPV center between January 1, 2015 and December 31, 2015 (n=1,496).
• Each case was matched with five controls on age, region, and time of first vaccine registration.
• The study population included 8,976 women.

Results:

• Women over 18 years old who had been referred to an HPV center were more likely to have used psychiatric medication or to have been hospitalized because of a psychiatric disorder within 5 years prior to the first vaccine registration.
• Referred women were more likely to have used antipsychotics, antidepressants, attention deficit hyperactivity disorder (ADHD) medication, or anxiolytics, and to have been hospitalized for affective disorders or anxiety, but not to have been hospitalized for schizoid, ADHD or eating disorders.
• These women were more likely to have had talk therapy or psychometric test performed prior to vaccination.
• Referred women of all ages had higher use of GP before vaccination.
• Population attributable fraction analyses indicated that psychiatric medication, hospitalization due to a psychiatric disorder, and use of talk therapy, or psychometric test “explained” 13%, 10%, 12%, and 11% of the referrals, respectively.
• Results did not change substantially when adjusted for potential confounders.