Patterns of use of symptomatic treatments for Alzheimer's disease dementia (AD).

BACKGROUND: Symptomatic treatment for Alzheimer's disease (AD) dementia could temporarily slow symptom worsening and improve the quality of life for both AD dementia patients and their caregivers. A comprehensive evaluation of symptomatic treatment patterns using recent data for newly diagnosed AD dementia has not been performed and compared across different countries. METHODS: The drug name, time to the first therapy, duration, discontinuation or switches were described in newly diagnosed AD dementia patients in two databases (a major U.S. health plan [US] and UK-Clinical Practice Research Datalink [CPRD GOLD]). This analysis included patients with newly diagnosed AD dementia in 2018-2019, who initiated symptomatic AD drug therapy, with ≥ 1 year baseline period and ≥ 1 year of follow-up. RESULTS: Over median follow-ups of 698 and 645 days, 63% and 65% of AD dementia patients used symptomatic treatments, with 34% and 77% newly initiating therapy, constituting analytic samples of 7637 patients in the US database and 4470 patients in the CPRD, respectively. The median time to the first therapy was 14 days for US and 49 days for CPRD; donepezil ranked the as most frequently used (69% vs 61%), followed by memantine (19% vs 28%) in the US database and CPRD, respectively. Median time on first therapy was 213 and 334 days, and 30% and 12% of patients proceeded to a second treatment in the US and CPRD databases, respectively. CONCLUSION: Approximately two thirds of newly diagnosed AD dementia patients utilized approved symptomatic treatment. Time on first therapy was relatively short (< 1 year) and the majority did not move to a second therapy, highlighting the need for better adherence and persistence to existing AD symptomatic therapies and the need for additional therapies to alleviate the significant burden of AD dementia.

Generate Analysis-Ready Data for Real-world Evidence: Tutorial for Harnessing Electronic Health Records With Advanced Informatic Technologies.

Although randomized controlled trials (RCTs) are the gold standard for establishing the efficacy and safety of a medical treatment, real-world evidence (RWE) generated from real-world data has been vital in postapproval monitoring and is being promoted for the regulatory process of experimental therapies. An emerging source of real-world data is electronic health records (EHRs), which contain detailed information on patient care in both structured (eg, diagnosis codes) and unstructured (eg, clinical notes and images) forms. Despite the granularity of the data available in EHRs, the critical variables required to reliably assess the relationship between a treatment and clinical outcome are challenging to extract. To address this fundamental challenge and accelerate the reliable use of EHRs for RWE, we introduce an integrated data curation and modeling pipeline consisting of 4 modules that leverage recent advances in natural language processing, computational phenotyping, and causal modeling techniques with noisy data. Module 1 consists of techniques for data harmonization. We use natural language processing to recognize clinical variables from RCT design documents and map the extracted variables to EHR features with description matching and knowledge networks. Module 2 then develops techniques for cohort construction using advanced phenotyping algorithms to both identify patients with diseases of interest and define the treatment arms. Module 3 introduces methods for variable curation, including a list of existing tools to extract baseline variables from different sources (eg, codified, free text, and medical imaging) and end points of various types (eg, death, binary, temporal, and numerical). Finally, module 4 presents validation and robust modeling methods, and we propose a strategy to create gold-standard labels for EHR variables of interest to validate data curation quality and perform subsequent causal modeling for RWE. In addition to the workflow proposed in our pipeline, we also develop a reporting guideline for RWE that covers the necessary information to facilitate transparent reporting and reproducibility of results. Moreover, our pipeline is highly data driven, enhancing study data with a rich variety of publicly available information and knowledge sources. We also showcase our pipeline and provide guidance on the deployment of relevant tools by revisiting the emulation of the Clinical Outcomes of Surgical Therapy Study Group Trial on laparoscopy-assisted colectomy versus open colectomy in patients with early-stage colon cancer. We also draw on existing literature on EHR emulation of RCTs together with our own studies with the Mass General Brigham EHR.

Contribution of Comorbid Conditions to the Diagnosis of Insomnia: A Database Study in a Commercially Insured Population.

ABSTRACT: Insomnia is a common sleep disorder characterized as dissatisfaction with sleep quantity or quality resulting in distress or impairment of social, occupational, or other daily functioning. It is unknown if there are medical conditions that have strong associations with insomnia but are unrecognized in previous literature. In this cross-sectional study based on IBM Marketscan Research Databases, we measured insomnia and 78 medical conditions in patients with 2-year continuous enrollment during 2018-2019. We selected important comorbidities associated with insomnia for eight age-sex groups and built logistic regression models to measure the associations. The prevalence of diagnosed insomnia increased with age, from <0.4% in the age group 0-17 to 4%-5% in the age group ≥65. Females had a higher prevalence of insomnia than males. Anxiety and depression were two important comorbidities across all age-sex subgroups. Most odds ratios of comorbidities remained significant after adjusting for other comorbidities in regression models. We did not find any new medical conditions that had strong associations with insomnia but were unrecognized in previous literature. The findings can help physicians use comorbidities to identify patients with high risk of insomnia.

Temporal Trends in Clinical Evidence of 5-Year Survival Within Electronic Health Records Among Patients With Early-Stage Colon Cancer Managed With Laparoscopy-Assisted Colectomy vs Open Colectomy.

Importance: Temporal shifts in clinical knowledge and practice need to be adjusted for in treatment outcome assessment in clinical evidence. Objective: To use electronic health record (EHR) data to (1) assess the temporal trends in treatment decisions and patient outcomes and (2) emulate a randomized clinical trial (RCT) using EHR data with proper adjustment for temporal trends. Design, Setting, and Participants: The Clinical Outcomes of Surgical Therapy (COST) Study Group Trial assessing overall survival of patients with stages I to III early-stage colon cancer was chosen as the target trial. The RCT was emulated using EHR data of patients from a single health care system cohort who underwent colectomy for early-stage colon cancer from January 1, 2006, to December 31, 2017, and were followed up to January 1, 2020, from Mass General Brigham. Analyses were conducted from December 2, 2019, to January 24, 2022. Exposures: Laparoscopy-assisted colectomy (LAC) vs open colectomy (OC). Main Outcomes and Measures: The primary outcome was 5-year overall survival. To address confounding in the emulation, pretreatment variables were selected and adjusted. The temporal trends were adjusted by stratification of the calendar year when the colectomies were performed with cotraining across strata. Results: A total of 943 patients met key RCT eligibility criteria in the EHR emulation cohort, including 518 undergoing LAC (median age, 63 [range, 20-95] years; 268 [52%] women; 121 [23%] with stage I, 165 [32%] with stage II, and 232 [45%] with stage III cancer; 32 [6%] with colon adhesion; 278 [54%] with right-sided colon cancer; 18 [3%] with left-sided colon cancer; and 222 [43%] with sigmoid colon cancer) and 425 undergoing OC (median age, 65 [range, 28-99] years; 223 [52%] women; 61 [14%] with stage I, 153 [36%] with stage II, and 211 [50%] with stage III cancer; 39 [9%] with colon adhesion; 202 [47%] with right-sided colon cancer; 39 [9%] with left-sided colon cancer; and 201 [47%] with sigmoid colon cancer). Tests for temporal trends in treatment assignment (χ2 = 60.3; P < .001) and overall survival (χ2 = 137.2; P < .001) were significant. The adjusted EHR emulation reached the same conclusion as the RCT: LAC is not inferior to OC in overall survival rate with risk difference at 5 years of -0.007 (95% CI, -0.070 to 0.057). The results were consistent for stratified analysis within each temporal period. Conclusions and Relevance: These findings suggest that confounding bias from temporal trends should be considered when conducting clinical evidence studies with long time spans. Stratification of calendar time and cotraining of models is one solution. With proper adjustment, clinical evidence may supplement RCTs in the assessment of treatment outcome over time.

DNA mismatch repair and microsatellite instability in colorectal tumors: an observational study in the Veterans Affairs Health Care System.

Background: Challenges in identifying microsatellite instability (MSI)/mismatch repair (MMR)-tested colorectal carcinoma (CRC) patients in electronic health records have led to gaps in the understanding of MSI-high/deficient mismatch repair prevalence. Methods: An algorithm to identify MSI-/MMR-tested Veterans Affairs patients was developed and an observational study of adult CRC patients with MSI/MMR testing from 2010 to 2018 was undertaken. Results: An optimized model to identify MSI-/MMR-tested patients yielded high positive predictive value (89.0%) and specificity (97.8%). The authors observed MSI-high/deficient mismatch repair CRC in 54 of 291 patients (18.6%); highest frequencies were observed in stages II (25.9%) and III (22.6%) and lowest in stage IV (5.8%). Conclusions: In this real-world study, the authors proposed a novel method of identifying MSI-/MMR-tested patients. Further validation and refinement of this model, and study in a larger CRC cohort, is warranted.

Epidemiology of Treatment-Resistant Depression in the United States.

Background: The prevalence of treatment-resistant depression (TRD) among patients with pharmaceutically treated depression (PTD) varies greatly in publications. The aim of this study is to estimate the prevalence of TRD using 2 large claims databases in the US.Methods: This cross-sectional study used data from the Humana and Optum databases. Patients aged ≥ 18 years who had at least 1 diagnosis of major depressive disorder (ICD-10-CM codes: F32.xx, F33.xx) and 1 antidepressant prescription filled in 2018 were identified as having PTD. Among patients with PTD, TRD was defined as experiencing failure of treatment with at least 2 antidepressants with ≥ 4 weeks of adequate treatment. We estimated the age- and gender-standardized prevalence of TRD and then used logistic regression to investigate if TRD risk varies by age, sex, race, and geographic region. Finally, we described the timeline of TRD development in incident PTD patients.Results: We identified 296,055 and 277,941 patients with PTD in the Humana and Optum databases, among whom 17,640 (6.0%) and 16,131 (5.8%) had TRD. After age and sex standardization, TRD prevalence among PTD patients was 6.8% in Humana vs 5.8% in Optum. Females, middle-aged adults, and White patients had higher risk of TRD. The median time from index antidepressant use to TRD was about 6 months in incident PTD patients.Conclusions: The prevalence of TRD among patients with PTD was similar in the 2 databases. TRD prevalence varies by sex, race, and age, with a higher prevalence in females, White patients, and those in the age group of 45-64 years. However, the absolute differences were small.

Replication of Oncology Randomized Trial Results using Swedish Registry Real World-Data: A Feasibility Study.

Nationwide healthcare registries are potential important real-world data (RWD) sources for assessing drug effectiveness in oncology. However, it is unclear whether registry-derived RWD are suitable for clinical development. In this study, we replicate results from the comparator arm of two previously published oncology randomized controlled trials (RCTs) using RWD from Swedish nationwide healthcare registries. For replication 1, the RCT included 553 patients and the RWD included 283 patients treated with sorafenib for advanced hepatocellular cancer. The median overall survival (OS) was 11.2 (95% confidence interval (CI): 10.1-13.2) months in the RCT and 8.2 (95% CI: 7.0-9.9) months in the RWD, unadjusted hazard ratio (HR) 0.75 (95% CI: 0.63-0.88). For time-to-treatment discontinuation (TTD), the HR was 1.00 (95% CI: 0.87-1.16). For replication 2, the RCT included 154 patients and the RWD included 704 patients treated with melphalan, prednisone, and thalidomide for untreated multiple myeloma. The median OS was 52.6 (95% CI: 40-not applicable) months in the RCT and 36.9 (95% CI: 33.8-40.5) months in the RWD, unadjusted HR 0.67 (95% CI: 0.51-0.87). For TTD, the HR was 0.89 (95% CI: 0.74-1.06). The results were similar when applying various propensity-based confounding adjustments. In conclusion, OS was shorter in the RWD, whereas TTD was similar. Importantly, the data necessary (ex: eligibility criteria and baseline confounders) for replicating RCTs was mostly not available and these results further underscore the importance of developing frameworks for capturing relevant patient-level RWD for clinical and regulatory decision making in oncology.

Medications in Patients with Dementia and Behavioral Disturbance.

BACKGROUND: Behavioral disturbance (BD) is common in dementia patients, with no FDA approved medications for this condition. Little data exists on the real-world medication use in this population. OBJECTIVE: To describe real-world medications use in this population. METHODS: A cross-sectional study was conducted using the MarketScan database for outpatient medications and the Cerner database for inpatient medications. The study period was Oct 2015-Jun 2018. Patients with dementia and BD were identified through ICD-10-CM. We examined outpatient medications prescribed during 6-month before or after BD event date, and inpatient medications during inpatient visits, especially on central nervous systems (CNS) drugs including antidementia drugs, antidepressants, antipsychotics, anxiolytics, and anticonvulsants. RESULTS: A total of 56,544 outpatients and 34,245 patient hospitalizations were assessed separately. Among outpatients, patients filled more medications after a BD event. The use of the five CNS drug classes generally increased after a BD event, and the largest increase was seen in antipsychotics (23%to 33%). Among inpatients, the median number of medications used in each hospitalization was 14. The use of antipsychotics was particularly high (64%), followed by anxiolytics (51%). A list of 60 unique medications were suggested to be the commonly used drugs in dementia patients with BD. CONCLUSION: In dementia patients with BD, anti-dementia medications, antidepressants, anticonvulsants, hypnotics and antipsychotics were the most used drug classes. Antidepressants and antipsychotics use were more frequent after a BD event, which suggests a need for safe drugs targeting BD in dementia patients.

Augmenting Real-World Data Through Modeling Key Clinical Trial Eligibility Criteria: An Example of Patients With Non-small-Cell Lung Cancer Treated With Pembrolizumab.

PURPOSE: To compare and characterize baseline characteristics and overall survival (OS) differences by key oncology eligibility criteria for real-world patients from the Flatiron Health database with advanced non-small-cell lung cancer (NSCLC) who received pembrolizumab monotherapy. METHODS: Real world data (RWD) were from the Flatiron Health advanced NSCLC database and include patients who initiated pembrolizumab monotherapy (first, second, or third line of therapy) by November 30, 2019. At the data cutoff (May 31, 2020), the median survival follow-up time was 8.4 months. Eligible patients satisfy the criteria of Eastern Cooperative Oncology Group performance status of 0/1 and laboratory values indicative of adequate organ function. RWD were analyzed for all patients and patients with a programmed cell death ligand-1 tumor proportion score ≥ 1%. Patients were divided into three categories: ineligible, eligible, and unknown (who satisfy all observed criteria, with at least one missing). An augmented population was also formed, which combines the latter two groups through a propensity-based adjustment. RESULTS: At the data cutoff, N = 3,877 patients with NSCLC received pembrolizumab monotherapy (1L = 2,682, 2L = 946, and 3L = 249). OS was consistently lower for the ineligible with similar survival for the eligible and augmented. Among all patients, the median OS in months (95% CI) was 8.2 (7.5 to 9.6), 16.3 (14.5 to 18.4), 16.4 (15.1 to 19.3), and 16.8 (15.6 to 18.5) for the ineligible (47%, n = 1,827), unknown (27%, n = 1,045), eligible (26%, n = 1,005), and augmented, respectively. The results were similar for patients with a programmed cell death ligand-1 tumor proportion score ≥ 1%. CONCLUSION: Real-world patients who received pembrolizumab monotherapy and meet key clinical eligibility criteria exhibited similar baseline characteristics and OS profiles as the unknown and augmented patient groups. Population augmentation is a feasible approach for improving the power of RWD analysis.

Real-world evidence to support regulatory decision making: New or expanded medical product indications.

There is increasing interest in utilizing real-world data (RWD) to produce real-world evidence (RWE) on the benefits and risks of medical products that could support regulatory approval decisions. The field of pharmacoepidemiology has a long history of focusing on data and evidence that would now be termed "real-world," including evidence from healthcare claims, registries, and electronic health records. However, several emerging trends over the past decade are converging to support the use of these and other RWD sources for approval decisions, and there are several recent examples and ongoing research that demonstrate how RWE may be used to support regulatory approval of new or expanded indications. The goal of this article is to review the current landscape and future directions of the use of RWE in this context. This manuscript is endorsed by the International Society for Pharmacoepidemiology (ISPE).

Human papillomavirus genotype-specific risks for cervical intraepithelial lesions.

Prevalence of different HPV genotypes is changing after HPV vaccination. The associated risks are needed for optimizing cervical cancer screening.To estimate HPV type-specific prevalence, odds ratio (OR), and positive predictive value (PPV) for cervical cytological abnormalities, we determined 41 different HPV genotypes in cervical samples from a population-based sample of 8351 women aged 18-51 years before HPV vaccination era (V501-033; NCT01077856).Prevalence of HPV16 was 4.9% (95% CI: 4.4-5.5) with the PPV for high-grade cytology 11.2%, and OR 11.9 (95% CI: 8.5-16.5). Carcinogenic HPVs included in the nonavalent vaccine (HPV16,18,31,33,45,52,58) had a population prevalence of 14.4% (95% CI: 13.5-15.4), with PPV of 8.0% (95% CI: 6.8-9.3) and OR 23.7 (95% CI: 16.0-63.5) for high-grade cytology. HPV types currently included in most screening tests, but not vaccinated against (HPV35,39,51,56,59,66,68) had a joint prevalence of 8.5% (95% CI: 7.8-9.2) with PPV of 4.4% (95% CI: 3.3-5.7) and OR of 2.9 (95% CI: 2.0-4.0) for high-grade cytology. The other 27 non-carcinogenic genotypes had a prevalence of 11.8%, PPV of 2.9% (95% CI:2.1-3.9), and OR 1.5 (95% CI: 1.1-2.2.) for high-grade cytology.These results suggest that HPV screening tests in the post-vaccination era might perform better if restricted to the HPV types in the nonavalent vaccine and screening for all 14 HPV types might result in suboptimal balance of harms and benefits.

Association of programmed death ligand 1 expression with prognosis among patients with ten uncommon advanced cancers.

AIM: PD-L1 expression and high levels of microsatellite instability (MSI-H) may predict response to checkpoint inhibitors, but their prevalence and prognostic value are unknown in many cancers. METHODS: We retrospectively evaluated PD-L1 combined positive score (CPS) and MSI-H and their association with clinical outcomes among patients with ten advanced uncommon cancers. RESULTS: 398 of 426 patients (93%) had a valid PD-L1 result; most (242; 61%) had CPS ≥1. Prevalence of MSI-H tumors was 8/360. Median overall survival was shorter among patients with PD-L1 CPS ≥1 tumors after first-line treatment (23.0 vs 39.7 months, p = 0.014). CONCLUSION: PD-L1 was commonly expressed in solid tumors, and CPS ≥1 was associated with shorter overall survival. Prevalence of MSI-H was low.

Emergency contraceptive pill use among women in Denmark, Norway and Sweden: Population-based survey.

INTRODUCTION: Emergency contraceptive pill (ECP) use is reported to have increased in several countries over time. In this multi-country population-based questionnaire study, we aimed to describe the patterns of ECP use and identify factors associated with its use. MATERIAL AND METHODS: In 2011-2012, women aged 18-45 years were randomly selected from national registers in Denmark, Norway and Sweden and invited to respond to questions related to lifestyle and contraceptive use. We used generalized logistic models to estimate odds ratios (ORs) and 95% confidence intervals (CI) comparing women who had used ECP with women who had never used ECP. RESULTS: Of the 45 445 women, 33.9% (Denmark = 32.3%, Norway = 35.1%, Sweden = 34.6%) had used ECP at least once in their lifetime. Among ECP users, 15.8% had used ECP within the last year and 50.0% had used ECP more than once in their life. After adjusting for country, age at response and response type, ECP use was associated with higher education (OR 2.09, 95% CI 1.54-2.84) and being single, divorced or widowed (OR 3.17, 95% CI 2.87-3.49). Binge drinking and smoking increased the odds of ECP use. Furthermore, early age at first intercourse (OR 1.29, 95% CI 1.08-1.55), having a new partner in the last 6 months (≥3 partners: OR 6.44, 95% CI 5.46-7.60) and lack of condom use with a recent new partner (OR 1.42, 95% CI 1.22-1.66) were found to be associated with ECP use. CONCLUSIONS: Our study shows that ECP use is common among Scandinavian women. Higher education and being single were associated with increased odds of ECP use. Risk behaviors such as smoking and early age at first sex were also associated with increased odds of ECP use. Since ECP use is not protective against sexually transmitted infections, our findings highlight the need to encourage awareness and regular use of condoms to prevent sexually transmitted diseases in women.

Clinical Pan-Cancer Assessment of Mismatch Repair Deficiency Using Tumor-Only, Targeted Next-Generation Sequencing.

PURPOSE: Given regulatory approval of immune checkpoint inhibitors in patients with mismatch repair-deficient (MMR-D) cancers agnostic to tumor type, it has become important to characterize occurrence of MMR-D and develop cost-effective screening approaches. Using a next-generation sequencing (NGS) panel (OncoPanel), we developed an algorithm to identify MMR-D frequency in tumor samples and applied it in a clinical setting with pathologist review. METHODS: To predict MMR-D, we adapted methods described previously for use in NGS panels, which assess patterns of single base-pair insertion or deletion events occurring in homopolymer regions. Tumors assayed with OncoPanel between July 2013 and July 2018 were included. For tumors tested after June 2017, sequencing results were presented to pathologists in real time for clinical MMR determination, in the context of tumor mutation burden, other mutational signatures, and clinical data. RESULTS: Of 20,301 tumors sequenced, 2.7% (553) were retrospectively classified as MMR-D by the algorithm. Of 4,404 samples with pathologist sign-out of MMR status, the algorithm classified 147 (3.3%) as MMR-D: in 116 cases, MMR-D was confirmed by a pathologist, five cases were overruled by the pathologist, and 26 were assessed as indeterminate. Overall, the highest frequencies of OncoPanel-inferred MMR-D were in endometrial (21%; 152/723), colorectal (9.7%; 169/1,744), and small bowel (9.3%; 9/97) cancers. When algorithm predictions were compared with historical MMR immunohistochemistry or polymerase chain reaction results in a set of 325 tumors sequenced before initiation of pathologist assessment, the overall sensitivity and specificity of the algorithm were 91.1% and 98.2%, respectively. CONCLUSION: We show that targeted, tumor-only NGS can be leveraged to determine MMR signatures across tumor types, suggesting that broader biomarker screening approaches may have clinical value.

Age at first intercourse, number of partners and sexually transmitted infection prevalence among Danish, Norwegian and Swedish women: estimates and trends from nationally representative cross-sectional surveys of more than 100 000 women.

INTRODUCTION: Sexual behavior at the population level impacts on public health. Recent representative sexual behavior data are lacking. MATERIAL AND METHODS: Cross-sectional surveys in 2005 and 2012 on women age 18-45 years randomly selected from the general population in Denmark (n = 40 804), Norway (n = 30 331) and Sweden (n = 32 114). RESULTS: Median (interquartile range) age at first intercourse was 16 (15-18) years in Denmark, 17 (16-18) years in Norway, and 17 (15-18) years in Sweden. Women in the most recent birth cohort had sexual debut at the lowest age, and were most likely to have sexual debut before the legal age of consent. Proportions with debut age ≤14 years among women born 1989-1994 vs 1971-1976, odds ratio (95% confidence interval) were: 18.4% vs 10.9%, 1.95 (1.74-2.18) in Denmark, 12.9% vs 6.3%, 2.38 (2.01-2.82) in Norway, 17.8% vs 11.4%, 1.75 (1.55-1.98) in Sweden. Median (interquartile range) number of lifetime sexual partners was 6 (3-10) in Denmark, 5 (2-10) in Norway, and 6 (3-11) in Sweden. The proportion of women reporting >10 sexual partners was also highest in the most recent survey. The percentage with odds ratio (95% confidence interval) in 2012 vs 2005 surveys were: 24.9% vs 22.8%, 1.13 (1.07-1.18) for Denmark; 23.8% vs 19.8%, 1.27 (1.19-1.34) for Norway; and 28.3% vs 23.8%, 1.31 (1.24-1.38) for Sweden. Similarly, the proportion of women reporting ever having had a sexually transmitted infection among women age <30 years were: 29.4% vs 26.4%, 1.21 (1.13-1.31) in Denmark, 28.9% vs 25.0%, 1.20 (1.10-1.31) in Norway, and 29.4% vs 22.2%, 1.45 (1.33-1.58) in Sweden. CONCLUSIONS: Scandinavian women reported lower age at first intercourse in younger birth cohorts. Moreover, they reported more lifetime sexual partners and a higher prevalence of ever having a sexually transmitted infection in 2012 than in 2005. Our findings may inform the interpretation of trends in outcomes associated with sexual health, and public health policies.

Human papillomavirus types in cervical high-grade lesions or cancer among Nordic women-Potential for prevention.

It is valuable to establish a population-based prevaccination baseline distribution of human papillomavirus (HPV) types among women with high-grade cervical intraepithelial neoplasia (CIN) grade 2 or 3 and cervical cancer in order to assess the potential impact of HPV vaccination. In four countries (Denmark, Norway, Sweden, and Iceland), we collected consecutive series of cervical cancers (n = 639) and high-grade precancerous cervical lesions (n = 1240) during 2004-2006 before implementation of HPV vaccination and subjected the specimens to standardized HPV genotyping. The HPV prevalence was 82.7% (95% confidence interval [CI] 79.0-86.4) in CIN2, 91.6% (95% CI 89.7-93.5) in CIN3, and 86.4% (95% CI 83.7-89.1) in cervical cancer. The most common HPV types in CIN2/3 were HPV16 (CIN2: 35.9%, 95% CI 31.2-40.6; CIN3: 50.2%, 95% CI 46.8-53.6) and HPV31 (CIN2: 10.9%, 95% CI 7.8-13.9; CIN3: 12.1%, 95% CI 9.9-14.3), while HPV16 and HPV18 were the most frequent types in cervical cancer (48.8%, 95% CI 44.9-52.7 and 15.3%, 95% CI 12.5-18.1, respectively). The prevalence of HPV16/18 decreased with increasing age at diagnosis in both CIN2/3 and cervical cancer (P < 0.0001). Elimination of HPV16/18 by vaccination is predicted to prevent 42% (95% CI 37.0-46.7) of CIN2, 57% (95% CI 53.8-60.5) of CIN3 and 64% (95% CI 60.3-67.7) of cervical cancer. Prevention of the five additional HPV types HPV31/33/45/52/58 would increase the protection to 68% (95% CI 63.0-72.2) in CIN2, 85% (95% CI 82.4-87.2) in CIN3 and 80% (95% CI 77.0-83.2) in cervical cancer. This study provides large-scale and representative baselines for assessing and evaluating the population-based preventive impact of HPV vaccination.

Contraceptive use at first intercourse is associated with subsequent sexual behaviors.

OBJECTIVE: Women's contraceptive use at first sexual intercourse (FSI) may be associated with subsequent sexual behaviors. We examined associations between contraceptive methods used at FSI and subsequent number of lifetime partners, induced abortions and sexually transmitted infections (STIs). STUDY DESIGN: During 2011-2012, we collected questionnaire data from a random sample of women aged 18-45 years from Denmark, Norway and Sweden. We used logistic regression and discrete-time proportional hazards models to estimate odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs), comparing different contraceptive methods used at FSI in the whole study sample and in women with FSI in 2001 or later [when emergency contraceptive pills (ECPs) were available without prescription]. RESULTS: Of 45,361 women in the study sample, those who did not use contraception at FSI (n=8155; 18.0%) were more likely than condom users to have ≥11 lifetime partners (OR=1.34; 95% CI 1.27-1.42), induced abortions (HR=1.62; 95% CI 1.53-1.71) and STIs (HR=1.15; 95% CI 1.10-1.20). ECP users (n=440, 1.0%) were more likely than condom users to have ≥11 lifetime partners (OR=1.76; 95% CI 1.40-2.22), induced abortions (HR=1.44; 95% CI 1.11-1.86) and STIs (HR=1.84; 95% CI 1.56-2.16). A similar pattern was seen in safe periods/withdrawal users. The associations did not change among women with FSI in 2001 or later (n=14,445). CONCLUSIONS: Compared with condom use, contraceptive nonuse, safe periods/withdrawal use and ECP use at FSI were associated with subsequent number of sexual partners, induced abortions and STIs. IMPLICATIONS: Contraceptive method used at first intercourse was associated with subsequent sexual behaviors in women. This study highlights the importance of early sexual behaviors and may help understand patterns of women's sexual behaviors.

Decline of HPV infections in Scandinavian cervical screening populations after introduction of HPV vaccination programs.

OBJECTIVE: To monitor the changes in prevalence of human papillomavirus (HPV) infections in women <50 years of age, participating in cervical screening programs of Denmark, Norway, and Sweden, before and after introduction of quadrivalent HPV (qHPV) vaccination. METHODS: Liquid-based cytology samples were collected from 6538 women who attended cervical screening in Denmark, Norway, and Sweden in 2006-2008 and from 6332 similarly enrolled women in 2012-2013. Denmark started organized qHPV vaccination in 2008, Norway in 2009, and Sweden in 2012. All HPV testing and genotyping was performed using identical enrollment and analysis methods, by accredited general primer polymerase chain reaction methods with typing using the Luminex system. RESULTS: Overall HPV positivity declined slightly from 36.5% in 2006-2008 to 34.5% in 2012-2013. The decline was most pronounced among women 18-26 years of age: from 54.4% to 48.1% (P < 0.001). The decline was substantial for vaccine HPV types (HPV6/11/16/18: decline from 22.3% to 16.6%; P < 0.001) and was seen for both low-risk vaccine types (HPV6/11 declined from 5.0% to 2.5%) and high-risk vaccine types (HPV16/18 declined from 18.9% to 14.9%). Among women 27-50 years of age, there was no change between the time periods (22.5% and 21.6%, respectively). The significant decline in the younger age group was different in the 3 countries. CONCLUSION: This population-based study enrolling >12,000 women participating in cervical screening in the 3 Nordic countries before and after introduction of organized qHPV vaccination demonstrated a marked decline in HPV infection in the younger population in the 2 countries where qHPV vaccination programs started in 2008-2009, suggesting that organized HPV vaccination programs resulted in a decrease of HPV types circulating in the general population.

Self-perceived risk of STIs in a population-based study of Scandinavian women.

OBJECTIVE: This study examined the associations between current behaviours/characteristics and self-perceived risk for STIs, among randomly selected women aged 18-45 years from Denmark, Norway and Sweden. METHOD: A population-based, cross-sectional, questionnaire study (paper based, web based and telephone based) was conducted during 2011-2012. We compared medium-high STI risk perception with no/low risk perception. The associations were explored for women who had ever had sexual intercourse and for women with a new partner in the last 6 months using multivariable logistic regression. RESULT: The overall prevalence of medium-high STI risk perception was 7.4%. It was highest among women aged 18-24 years (16.2%) and among the Danish women (8.8%). Number of new sexual partners in the last 6 months (≥3vs 0 partners, OR 14.94, 95% CI 13.20 to 16.94) was strongly associated with medium-high STI risk perception. Among women with a new partner in the last 6 months, lack of condom use increased medium-high STI risk perception (OR 1.73, 95% CI 1.52 to 1.96). Genital warts in the last year, binge drinking and being single were associated with increased risk perception and remained statistically significant after additional adjustments were made for number of new partners and condom use with new partners in the last 6 months. CONCLUSION: Subjective perception of risk for STI was associated with women's current risk-taking behaviours, indicating women generally are able to assess their risks for STIs. However, a considerable proportion of women with multiple new partners in the last 6 months and no condom use still considered themselves at no/low risk for STI.