Childhood vaccination among Polish immigrants in Norway: a qualitative study.

BACKGROUND: Confidence in childhood vaccination is high in Norway and the Norwegian Childhood Immunization Programme (NCIP) achieves high overall coverage rates. However, lower coverage has been observed for some immigrant groups, including Polish immigrants who represent the largest immigrant group in Norway. Anti-vaccine sentiments and increased refusal of mandatory childhood vaccination has been on the rise in Poland, but it is unknown whether such attitudes also apply to Polish immigrants in Norway, as they experience a different vaccination policy and perhaps also different attitudes to vaccines. This qualitative study aims to explore attitudes towards childhood vaccination in Norway among Polish immigrants. METHODS: We interviewed 15 Polish parents living in Norway in 2022. We recruited the participants by purposive sampling and analyzed the interviews by reflexive thematic analysis. RESULTS: Three themes were identified: views of childhood vaccination, vaccine hesitancy, and differences in childhood vaccination between Poland and Norway. Overall, the participants favored childhood vaccination and viewed most of the vaccines included in the NCIP as safe and reliable. Human papilloma virus, meningococcal and pneumococcal vaccines were declined by some of the parents. Comparisons of childhood vaccination in Poland and Norway was evident in many of the interviews, especially among parents whose children had received vaccines in both countries. The participants were well acquainted with the NCIP, favored voluntary childhood vaccination, and the majority expressed a high level of trust in Norwegian health authorities. CONCLUSIONS: Polish immigrants to Norway generally expressed positive views about childhood vaccination. Non-vaccination was related to lack of knowledge and/or unfamiliarity with certain vaccines and not with anti-vaccine sentiments or conspiracy theories. The study highlights how parents' knowledge, in combination with norms and trends from both birth country and country of residence, influence parents' decision making about vaccination.

Predictors of maternal pertussis vaccination acceptance among pregnant women in Norway.

Maternal vaccination against pertussis is safe and provides effective protection against pertussis for the newborn, but the vaccine coverage rate remains generally low. Norway is currently planning for introduction of routine maternal pertussis vaccination. To assess maternal pertussis vaccination acceptance among pregnant Norwegian women, we surveyed women at 20-40 weeks gestation in 2019. Among the 1,148 pregnant women participating in this cross-sectional study, 73.8% reported they would accept pertussis vaccination during pregnancy if it was recommended, 6.9% would not accept and 19.2% were undecided. Predictors for low likelihood of accepting pertussis vaccination during pregnancy included low confidence in health authorities and in maternal pertussis vaccination safety and effectiveness, low awareness and adherence to influenza vaccination during pregnancy, and low awareness of pertussis vaccination. The major reasons reported for not accepting or being undecided about maternal pertussis vaccination were lack of information on vaccine safety for both mother and child. Most women reported that they would consult their general practitioner or a midwife for information if they were offered maternal pertussis vaccination. General practitioners and midwives were also regarded as the most trustworthy sources of information if the women were in doubt about accepting vaccination. We conclude that information addressing safety concerns and raising awareness about maternal pertussis vaccination could increase acceptance of maternal pertussis vaccination. Our findings highlight the pivotal role of the antenatal and primary health care services in providing such information to pregnant women.

Sociodemographic characteristics associated with cervical cancer screening participation by send-to-all and opt-in HPV self-sampling: Who benefits? Results from a randomized controlled trial among long-term non-attending women in Norway.

With the objective to investigate associations between sociodemographic characteristics and participation in interventions designed to increase participation in cervical cancer screening among under-screened women, we randomized a random sample of 6000 women in Norway aged 35-69 years who had not attended cervical screening for ≥10 years to receive either (i) a reminder to attend regular screening (control), (ii) an offer to order a self-sampling kit (opt-in), or (iii) a self-sampling kit unsolicited (send-to-all). We analyzed how sociodemographic characteristics were associated with screening participation within and between screening arms. In the send-to-all arm, increased screening participation ranged from 17.1% (95% confidence interval [95% CI] = 10.3% to 23.8%) to 30.0% (95% CI = 21.5% to 38.6%) between sociodemographic groups. In the opt-in arm, we observed smaller, and at times, non-significant increases within the range 0.7% (95% CI = -5.8% to 7.3%) to 19.1% (95% CI = 11.6% to 26.7%). In send-to-all versus control comparisons, there was greater increase in participation for women in the workforce versus not (6.1%, 95% CI = 1.6% to 10.6%), with higher versus lower income (7.6%, 95% CI = 2.2% to 13.1%), and with university versus primary education (8.5%, 95% CI = 2.4% to 14.6%). In opt-in versus control comparisons, there was greater increase in participation for women in the workforce versus not (4.6%, 95% CI = 0.7% to 8.5%), with higher versus lower income (6.3%, 95% CI = 1.5% to 11.1%), but lower increase for Eastern European versus Norwegian background (-12.7%, 95% CI = -19.7% to -5.7%). Self-sampling increased cervical screening participation across all sociodemographic levels, but inequalities in participation should be considered when introducing self-sampling, especially with the goal to reach long-term non-attending women.

Vaccine coverage among children born to immigrant parents in Norway, 2000-2020.

BACKGROUND: The Norwegian Childhood Immunization Program maintains a high national coverage of 95-97% in the most recent years. Whether there are subgroups with lower uptake is less studied. This study examines pertussis and measles vaccination coverage among six immigrant groups in Norway. These vaccines are normally administered as part of different combination vaccines and their coverage rate indicate the national vaccination coverage against a range of additional infections. METHODS: Data from the Norwegian National Population Register were linked at individual level with vaccination data from the Norwegian Immunisation Registry. The final sample consisted of 53,052 children born during 2000-2018 in Norway to parents who were born in Iraq, Lithuania, Pakistan, Poland, Somalia, or Vietnam. Vaccination coverage was measured at 2-years of age. Multivariate linear regression was utilized to estimate the relationship between vaccinations status, year of birth, gender, mother's length of residency in Norway, and area of residence. RESULTS: At two years of age, the majority of the children were vaccinated. Coverage among the groups varied at, above, and below the national average for the two vaccines. For most of the years examined, children born by parents from Lithuania, Poland, and Somalia had lower coverage for the measles vaccine (range 81-84% in 2020) than the national level (97% in 2020). Children born by parents from the Eastern-European countries also had lower coverage than the national level for the pertussis vaccine (range 87-89% in 2020). DISCUSSION: This study illustrates how subgroups with lower vaccination coverage may exists within a well-established vaccination program with high national coverages. Differences in coverage were found for both vaccines, but the differences were more pronounced for the measles vaccine. The high vaccination coverage in Norway provides indirect protection through herd immunity for unvaccinated individuals, however, the lower vaccination coverage in some immigrant groups is a concern.

Quadrivalent HPV vaccine effectiveness against anogenital warts: A registry-based study of 2,2 million individuals.

BACKGROUND: In 2009, Norway initiated routine quadrivalent HPV (qHPV) vaccination for girls at 12-13 years of age to protect against virus types causing cervical cancer, HPV16/18, and HPV6/11 which cause anogenital warts (AGW). We wanted to investigate qHPV vaccine effectiveness (VE) against AGW in females before and after first AGW episode and to assess the impact of female vaccination in males. MATERIALS AND METHODS: QHPV vaccination and AGW episodes were collected for the time period 2006-2016 for birth cohorts 1975-2003. Cox models were applied to age at first, as well as at second AGW episode. Finally, we estimated the impact of the female vaccination program on unvaccinated males. RESULTS: The VE against the first episode of AGW was strongly dependent on vaccination age, with hazard ratios (HRs) compared to unvaccinated individuals of 0.2, 0.2, 0.3, 0.5, 1.0, 1.3, and 2.7, for age groups of ⩽13, 14-15, 16-17, 18-19, 20-24, 25-29, and 30+ years at first vaccination, respectively. Among women who had suffered a first episode of AGW, subsequent qHPV vaccination did not protect against a second episode, with HRs of 0.8, 1.0, and 1.4, for age groups of ⩽17, 18-24, and 25+ years at first vaccination. A gradually decreasing AGW risk was seen in unvaccinated male cohorts neighboring the first routinely vaccinated female 1997 cohort. CONCLUSIONS: When administered before 14 years of age, qHPV vaccination reduced the probability of AGW about fivefold. The effect decreased sharply with vaccination age, and was not significant among women vaccinated after age 20 years. QHPV administered after the first AGW episode did not protect against a second AGW episode. Herd effects were indicated in unvaccinated males, as we observed a gradual decrease in AGW rates from the 1993 male birth cohort and onwards.

Unpacking the Lay Epidemiology of Cervical Cancer: A Focus Group Study on the Perceptions of Cervical Cancer and Its Prevention among Women Late for Screening in Norway.

Nonattendance for cervical cancer screening is often understood in terms of a lack of 'appropriate' or 'correct' knowledge about the risks and prevention of the disease. Few studies have explored how lay persons-the users themselves-interpret and contextualise scientific knowledge about cervical cancer. In this study, we address the following research question: How is the epidemiology of cervical cancer and its prevention discussed among women who are late for cervical cancer screening in Norway? We completed nine focus group interviews (FGIs) with 41 women who had postponed cervical screening. The analyses were both inductive and explorative, aiming to unpack the complexity of lay understandings of cervical cancer. Interactive associations expressed in the FGIs reflected multiple understandings of aetiology and risk factors, screening, and interpretations of responsibility for acquiring cervical cancer. The term 'candidacy' was employed to provide an enhanced understanding of lay reasoning about the explanations and predictions of cervical cancer, as reflected in the FGIs. Both interpretations of biomedical concepts and cultural values were used to negotiate acceptable and nuanced interpretations of candidacy for cervical cancer. Uncertainties about risk factors for acquiring cervical cancer was an important aspect of such negotiations. The study's findings provide an in-depth understanding of the contexts in which screening may be rendered less relevant or significant for maintaining health. Lay epidemiology should not be considered inappropriate knowledge but rather as a productive component when understanding health behaviours, such as screening attendance.

Factors associated with teenage pregnancy in the Scandinavian countries.

AIMS: Teenage pregnancy may have negative consequences for the mother and the infant. The aim of the study was to examine whether selected individual factors occurring early in life were associated with teenage pregnancy. METHODS: In a population-based, cross-sectional questionnaire study among 34,455 women from Denmark, Norway, and Sweden aged 20-45 years, who had first sexual intercourse (FSI) at age 13-19 years, we assessed the association between early smoking and drinking initiation (i.e., before the age of 13), contraceptive use at FSI, and teenage pregnancy. Log-linear binary regression models were fitted to estimate the relative risk (RR) with 95% confidence intervals (CIs) of teenage pregnancy according to the three exposure variables, overall and by age at FSI. Furthermore, the outcomes of the teenage pregnancies were examined according to age at FSI. RESULTS: Teenage pregnancy occurred in 11% of the population. Both early smoking initiation (RR: 1.6; 95% CI: 1.4-1.8), early drinking initiation (RR: 1.2; 95% CI: 1.0-1.4), and non-use of contraceptives at FSI (RR: 1.9; 95% CI: 1.8-2.0) were associated with teenage pregnancy. The associations for early smoking initiation and non-use of contraceptives remained when analyses were stratified by age at FSI. Almost 60% of all teenage pregnant women had an induced abortion and less than 30% gave birth. CONCLUSIONS: Individual factors, including early smoking and drinking initiation, and non-use of contraceptives at FSI, were associated with teenage pregnancy regardless of age at FSI. This emphasizes the necessity of focusing on early risk-taking behavior as a potential modifier to prevent teenage pregnancy.

Coverage of primary and booster vaccination against COVID-19 by socioeconomic level: A nationwide cross-sectional registry study.

High and equitable COVID-19 vaccination coverage is important for pandemic control and prevention of health inequity. However, little is known about socioeconomic correlates of booster vaccination coverage. In this cross-sectional study of all Norwegian adults in the national vaccination program (N = 4,190,655), we use individual-level registry data to examine coverage by levels of household income and education of primary (≥2 doses) and booster (≥3 doses) vaccination against COVID-19. We stratify the analyses by age groups with different booster recommendations and report relative risk ratios (RR) for vaccination by 25 August 2022. In the 18-44 y group, individuals with highest vs. lowest education had 94% vs. 79% primary coverage (adjusted RR (adjRR) 1.15, 95%CI 1.14-1.15) and 67% vs. 38% booster coverage (adjRR 1.55, 95% CI 1.55-1.56), while individuals with highest vs. lowest income had 94% vs. 81% primary coverage (adjRR 1.10, 95%CI 1.10-1.10) and 60% vs. 43% booster coverage (adjRR 1.23, 95%CI 1.22-1.24). In the ≥45 y group, individuals with highest vs. lowest education had 96% vs. 92% primary coverage (adjRR 1.02, 95%CI 1.02-1.02) and 88% vs. 80% booster coverage (adjRR 1.09, 95%CI 1.09-1.09), while individuals with highest vs. lowest income had 98% vs. 82% primary coverage (adjRR 1.16, 95%CI 1.16-1.16) and 92% vs. 64% booster coverage (adjRR 1.33, 95%CI 1.33-1.34). In conclusion, we document large socioeconomic inequalities in COVID-19 vaccination coverage, especially for booster vaccination, even though all vaccination was free-of-charge. The results highlight the need to tailor information and to target underserved groups for booster vaccination.

Real-world effectiveness of HPV vaccination against cervical neoplasia among birth cohorts ineligible for routine vaccination.

Human papillomavirus (HPV) vaccine effectiveness may differ between settings. Here we present the first real-world effectiveness study of HPV vaccination on high-grade cervical lesions from Norway, among women who received HPV vaccine outside the routine program. We performed an observational study of all Norwegian women born 1975 to 1996 and retrieved individual data from nationwide registries on HPV vaccination status and incidence of histologically verified high-grade cervical neoplasia during 2006 to 2016. We estimated the incidence rate ratio (IRR) and 95% confidence intervals (CI) for vaccination vs no vaccination by Poisson regression stratified by age at vaccination <20 years and ≥20 years. The cohort consisted of 832 732 women, of which 46 381 (5.6%) received at least one dose of HPV vaccine by the end of 2016. The incidence rate of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) increased with age regardless of vaccination status and was highest at age 25 to 29, at 637/100 000 among unvaccinated women, 487/100 000 among women vaccinated before age 20 and 831/100 000 among women vaccinated at age 20 or older. The adjusted IRR of CIN2+ between vaccinated and unvaccinated women was 0.62 (95% CI: 0.46-0.84) for women vaccinated below age 20, and 1.22 (95% CI: 1.03-1.43) for women vaccinated at age 20 or older. These findings indicate that HPV vaccination among women too old to be eligible for routine HPV vaccination is effective among women who are vaccinated below age 20 but may not have the desired impact among women who are vaccinated at age 20 or older.

The cost-effectiveness of opt-in and send-to-all HPV self-sampling among long-term non-attenders to cervical cancer screening in Norway: The Equalscreen randomized controlled trial.

OBJECTIVE: We assessed the cost-effectiveness of mailing a human papillomavirus self-sampling (HPV-ss) kit, directly or via invitation to order, compared with mailing reminder letters among long-term non-attenders in Norway. METHODS: We conducted a secondary analysis using the Equalscreen study data with 6000 women aged 35-69 years who had not screened in 10+ years. Participants were equally randomized into three arms: reminder letter (control); invitation to order HPV-ss kit (opt-in); directly mailed HPV-ss kit (send-to-all). Cost-effectiveness (2020 Great British Pounds (GBP)) was estimated using incremental cost-effectiveness ratios (ICERs) per additional screened woman, and per additional cervical intraepithelial neoplasia grade 2 or worse (CIN2+) from extended and direct healthcare perspectives. RESULTS: Participation, CIN2+ detection, and total screening costs were highest in the send-to-all arm, followed by the opt-in and control arms. Non-histological physician appointments contributed to 67% of the total costs in the control arm and ≤ 31% in the self-sampling arms. From an expanded healthcare perspective, the ICERs were 135 GBP and 169 GBP per additional screened woman, and 2864 GBP and 4165 GBP per additional CIN2+ detected for the opt-in and send-to-all, respectively. CONCLUSIONS: Opt-in and send-to-all self-sampling were more effective and, depending on willingness-to-pay, may be considered cost-effective alternatives to improve screening attendance in Norway.

Risk factors for head and neck cancer in more and less developed countries: Analysis from the INHANCE consortium.

OBJECTIVE: We analyzed the pooled case-control data from the International Head and Neck Cancer Epidemiology (INHANCE) consortium to compare cigarette smoking and alcohol consumption risk factors for head and neck cancer between less developed and more developed countries. SUBJECTS AND METHODS: The location of each study was categorized as either a less developed or more developed country. We compared the risk of overall head and neck cancer and cancer of specific anatomic subsites associated with cigarette smoking and alcohol consumption. Additionally, age and sex distribution between categories was compared. RESULTS: The odds ratios for head and neck cancer sites associated with smoking duration differed between less developed and more developed countries. Smoking greater than 20 years conferred a higher risk for oral cavity and laryngeal cancer in more developed countries, whereas the risk was greater for oropharynx and hypopharynx cancer in less developed countries. Alcohol consumed for more than 20 years conferred a higher risk for oropharynx, hypopharynx, and larynx cancer in less developed countries. The proportion of cases that were young (<45 years) or female differed by country type for some HNC subsites. CONCLUSION: These findings suggest the degree of industrialization and economic development affects the relationship between smoking and alcohol with head and neck cancer.

HPV self-sampling among long-term non-attenders to cervical cancer screening in Norway: a pragmatic randomised controlled trial.

BACKGROUND: Cervical cancer screening participation is suboptimal in most settings. We assessed whether human papillomavirus (HPV) self-sampling may increase screening participation among long-term non-attenders in Norway. METHODS: A pragmatic randomised controlled trial with participation as the primary outcome was initiated in the national cervical screening programme in March 2019. A random sample of 6000 women aged 35-69 years who had not attended screening for at least 10 years were randomised 1:1:1 to receive either (i) a reminder to attend regular screening (control), (ii) an offer to order a self-sampling kit (opt-in) for HPV testing or (iii) a self-sampling kit unsolicited (send-to-all) for HPV testing. RESULTS: Total participation was 4.8%, 17.0% and 27.7% among control, opt-in and send-to-all (P < 0.0001; participation difference (%) send-to-all vs. control: 22.9 (95%CI: 20.7, 25.2); opt-in vs. control: 12.3 (95%CI: 10.3, 14.2); send-to-all vs. opt-in: 10.7 (95% CI: 8.0, 13.3)). High-risk HPV was detected in 11.5% of self-samples and 9.2% of clinician-collected samples (P = 0.40). Most women (92.5%) who returned a positive self-sample attended the clinic for triage testing. Of the 933 women screened, 33 (3.5%) had CIN2 + (1.1%, 3.7%, 3.8% among control, opt-in, and send-to-all, respectively), and 11 (1.2%) had cervical cancer (0%, 1.2%, 1.3% among control, opt-in, send-to-all, respectively). CONCLUSION: Opt-in and send-to-all self-sampling increased screening participation among long-term, higher-risk non-attenders. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT03873376.

Nasopharyngeal carcinoma patients from Norway show elevated Epstein-Barr virus IgA and IgG antibodies prior to diagnosis.

BACKGROUND: IgA antibodies against few Epstein-Barr virus (EBV) proteins are established serological markers for nasopharyngeal carcinoma (NPC). We recently validated a novel, comprehensive EBV marker panel and showed that IgA, but also IgG antibodies against multiple EBV proteins are highly sensitive and specific for EBV-positive NPC at diagnosis. However, data about these novel biomarkers as prospective markers for NPC are sparse. METHODS: This study included 30 incident NPC cases and 60 matched controls from the Norwegian Janus Serum Bank. For 21 NPCs, molecular EBV and human papillomavirus (HPV) status were assessed by EBER-ISH and HPV DNA/RNA testing by PCR, respectively. IgA and IgG serum antibodies against 17 EBV antigens were analyzed in prediagnostic sera of cases (median lead time 14 years) and controls using multiplex serology. Sensitivities were calculated using receiver operating characteristic analysis pre-specified to yield 90% specificity in the control group. From 10 cases, serial samples were available. RESULTS: Quantitative EBV antibody levels were significantly elevated among all cases (p < 0.05) for three IgA and six IgG antibodies. The highest sensitivities for defining 12 EBER-ISH-positive NPCs were observed for BGLF2 IgA (67%) and BGLF2 IgG (83%). Increased IgA and IgG antibody levels between the first and last draw before diagnosis were observed for EBER-ISH positive, but not for EBER-ISH negative NPCs. Among 21 molecularly analyzed NPCs, 4 EBER-ISH negative NPCs showed concomitant positivity to HPV type-specific DNA and RNA; 3 NPCs were HPV16 and 1 NPC was HPV18 positive. CONCLUSION: Both, EBV IgA and IgG antibody levels are significantly elevated many years before diagnosis of EBV-positive NPCs in Norway, an NPC low-incidence region. This study provides insights into one of the largest available prospective sample collections of NPCs in a non-endemic country.

Switching clinic-based cervical cancer screening programs to human papillomavirus self-sampling: A cost-effectiveness analysis of vaccinated and unvaccinated Norwegian women.

Several countries have implemented primary human papillomavirus (HPV) testing for cervical cancer screening. HPV testing enables home-based, self-collected sampling (self-sampling), which provides similar diagnostic accuracy as clinician-collected samples. We evaluated the impact and cost-effectiveness of switching an entire organized screening program to primary HPV self-sampling among cohorts of HPV vaccinated and unvaccinated Norwegian women. We conducted a model-based analysis to project long-term health and economic outcomes for birth cohorts with different HPV vaccine exposure, that is, preadolescent vaccination (2000- and 2008-cohorts), multiage cohort vaccination (1991-cohort) or no vaccination (1985-cohort). We compared the cost-effectiveness of switching current guidelines with clinician-collected HPV testing to HPV self-sampling for these cohorts and considered an additional 44 strategies involving either HPV self-sampling or clinician-collected HPV testing at different screening frequencies for the 2000- and 2008-cohorts. Given Norwegian benchmarks for cost-effectiveness, we considered a strategy with an additional cost per quality-adjusted life-year below $55 000 as cost-effective. HPV self-sampling strategies considerably reduced screening costs (ie, by 24%-40% across cohorts and alternative strategies) and were more cost-effective than clinician-collected HPV testing. For cohorts offered preadolescent vaccination, cost-effective strategies involved HPV self-sampling three times (2000-cohort) and twice (2008-cohort) per lifetime. In conclusion, we found that switching from clinician-collected to self-collected HPV testing in cervical screening may be cost-effective among both highly vaccinated and unvaccinated cohorts of Norwegian women.

Germline determinants of humoral immune response to HPV-16 protect against oropharyngeal cancer.

Although several oropharyngeal cancer (OPC) susceptibility loci have been identified, most previous studies lacked detailed information on human papillomavirus (HPV) status. We conduct a genome-wide analysis by HPV16 serology status in 4,002 oral cancer cases (OPC and oral cavity cancer (OCC)) and 5,256 controls. We detect four susceptibility loci pointing to a distinct genetic predisposition by HPV status. Our most notable finding in the HLA region, that is now confirmed to be specific of HPV(+)OPC risk, reveal two independent loci with strong protective effects, one refining the previously reported HLA class II haplotype association. Antibody levels against HPV16 viral proteins strongly implicate the protective HLA variants as major determinants of humoral response against L1 capsid protein or E6 oncoprotein suggesting a natural immune response against HPV(+)OPC promoted by HLA variants. This indicates that therapeutic vaccines that target E6 and attenuate viral response after established HPV infections might protect against HPV(+)OPC.

Regional differences in cervical cancer incidence and associated risk behaviors among Norwegian women: a population-based study.

BACKGROUND: Cervical cancer incidence is influenced by screening and risk factors in the population. The main risk factor for cervical cancer is sexually transmitted human papillomavirus (HPV), which is sexually transmitted and thus associated with sexual behavior. Smoking, parity and hormonal contraceptive use may also be associated with cervical cancer risk. We compared incidence, screening coverage and risk behaviors for cervical cancer between health regions in Norway. METHODS: We obtained data on incidence of cervical cancer among Norwegian women during 1992-2016 and data on screening coverage from the Cancer Registry of Norway. We obtained data on sexual behavior and smoking from a population-based survey of 16,575 Norwegian women who were 18-45 years old in 2005. RESULTS: Cervical cancer incidence was higher in the northern and southeastern region than in the middle and western region (range in incidence per 100,000 person-years during 1992-2016; north: 10.5 to 14.6; southeast: 9.3 to 12.9; mid: 6.8 to 9.5; west: 8.4 to 10.0). The incidence decreased modestly in the north (average annual percentage change (95% confidence interval) - 1.0 (- 1.2 to - 0.7)) and southeast (- 0.7 (- 1.0 to - 0.3)), but did not change significantly in the mid (- 0.3 (- 1.0 to 0.4)) and west (- 0.3 (- 0.6 to 0.0)). Compared to the national average, women in the north had earlier sexual debut, more partners and higher prevalence of ever having had a sexually transmitted infection (STI), while the opposite was observed among women in the west. Women in the middle and southeastern regions tended to be similar to the national average for sexual behaviors. Although less pronounced, the prevalence of smoking showed regional patterns similar to that observed for sexual behaviors, while ever-use of hormonal contraceptives and cervical screening coverage was similar between regions. CONCLUSIONS: There were regional differences in cervical cancer incidence during the era of nationally organized cervical screening in Norway. To some extent, these differences corresponded to regional differences in risk behavior for cervical cancer in the Norwegian female population.

Sociodemographic Correlates of Human Papillomavirus Vaccine Uptake: Opportunistic and Catch-Up Vaccination in Norway.

Achieving equity in human papillomavirus (HPV) vaccination has high priority. In this nationwide registry-based study, we aimed to investigate sociodemographic correlates of HPV vaccine uptake among women who were vaccinated opportunistically at their own initiative and cost during October 2006-June 2018, and among women who were vaccinated free-of-charge in a catch-up vaccination program during November 2016-June 2018. For 840,328 female residents born in Norway between 1975 and 1996, we retrieved HPV vaccination and sociodemographic data from national registries. We used separate models to analyze the sociodemographic correlates of the initiation and completion of HPV vaccination in opportunistic and catch-up vaccination settings. Overall initiation rate for opportunistic HPV vaccination was 2.2%. Uptake increased consistently with birth year, maternal education level, and household income. Having two immigrant parents or a mother working in a lower prestige occupation was strongly associated with low opportunistic vaccination uptake. Similar but weaker inequities were observed in catch-up HPV vaccination. Initiation rate during the first 20 months of the catch-up program was 46.2%. Completion rate was 72.1% and 73.0% for opportunistic or catch-up vaccination, respectively, with small inequities. In conclusion, HPV vaccine uptake was strongly associated with sociodemographic background both in opportunistic and catch-up vaccination settings, with particularly low uptake associated with having two immigrant parents and low household income.

Impact and cost-effectiveness of strategies to accelerate cervical cancer elimination: A model-based analysis.

Following the global call for action by the World Health Organization to eliminate cervical cancer (CC), we evaluated how each CC policy decision in Norway influenced the timing of CC elimination, and whether introducing nonavalent human papillomavirus (HPV) vaccine would accelerate elimination timing and be cost-effective. We used a multi-modeling approach that captured HPV transmission and cervical carcinogenesis to estimate the CC incidence associated with six past and future CC prevention policy decisions compared with a pre-vaccination scenario involving 3-yearly cytology-based screening. Scenarios examined the introduction of routine HPV vaccination of 12-year-old girls with quadrivalent vaccine in 2009, a temporary catch-up program for females aged up to 26 years in 2016-2018 with bivalent vaccine, the universal switch to bivalent vaccine in 2017, expansion to include 12-year-old boys in 2018, the switch from cytology- to HPV-based screening for women aged 34-69 in 2020, and the potential switch to nonavalent vaccine in 2021. Introducing routine female vaccination in 2009 enabled elimination to be achieved by 2056 and prevented 17,300 cases. Cumulatively, subsequent policy decisions accelerated elimination to 2039. According to our modeling assumptions, switching to the nonavalent vaccine would not be considered 'good value for money' at relevant cost-effectiveness thresholds in Norway unless the incremental cost was $19 per dose or less (range: $17-24) compared to the bivalent vaccine. CC control policies implemented over the last decade in Norway may have accelerated the timeframe to elimination by more than 17 years and prevented over 23,800 cases by 2110.