Using Decision-Analytic Modeling to Isolate Interventions That Are Feasible, Efficient and Optimal: An Application from the Norwegian Cervical Cancer Screening Program

Systematic review of cost-effectiveness studies on cervical cancer screening across Europe

INTRODUCTION

Cervical cancer (CC) is a type of cancer with poor prognosis when diagnosed in advanced stage with a big socioeconomic burden. The incidence rates have wide variations among European countries depending on the implementation or not of screening, vaccination programs and the human development index (HDI). Most studies on cost-effectiveness of CC screening programs are carried out in countries with a high HDI, however more recent reviews of screening approaches are coming from countries with lower HDI aiming to identify the best screening strategies. Our study aims to identify which are the currently applied and most cost-effective strategies of CC screening in Europe.

MATERIALS AND METHODS

This is a systematic review conducted in three different databases (PubMed, Scopus and ScienceDirect) and reported following the PRISMA guidelines. General key terms for all databases were the following: cost-effectiveness, cervical cancer, screening, Europe. We included studies in English, Italian, Spanish and Bulgarian, published in the last 25 years, reporting data on cost-effectiveness of CC screening, costs and outcome measures. The methodological quality of the articles was evaluated with a standardized tool.

RESULTS

A total of 262 studies were identified and 22 studies were included in the final analysis. In 90.1 % of the economic studies, the new screening strategy was shown to be more cost-effective compared to the current one or compared to no screening. The optimal strategy mostly involved primary HPV testing, combined with cytology or as stand-alone screening technique. Several scenarios differing on starting age and periodicities for CC screening, combination of techniques and triage, were found to be cost-effective and below the willingness to pay (WTP) threshold. The methodology of all included studies was assessed from 10 to 11 on the JBI standardized tool and Drummond 11-point checklist.

CONCLUSION

Numerous cost-effective options for CC screening in different European countries were identified in this systematic review. HPV testing, with or without cytology, mainly starting at 30 years of age and repeated every 5 years or more was the most cost-effective technique. Future studies should focus on the most appropriate CC screening approach for each context and setting, also considering HPV vaccination in Europe.

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.

Cost-effectiveness of cervical cancer screening with primary HPV testing for unvaccinated women in Sweden

BACKGROUND

Sweden revised their cervical cancer screening program in 2017 to include cytology-based screening for women aged 23-29 years and primary human papillomavirus (HPV) testing for women aged 30-64 years; however, alternative strategies may be preferred. To inform cervical cancer prevention policies for unvaccinated women, we evaluated the cost-effectiveness of alternative screening strategies, including the current Swedish guidelines.

METHODS

We adapted a mathematical simulation model of HPV and cervical cancer to the Swedish context using primary epidemiologic data. We compared the cost-effectiveness of alternative screening strategies that varied by the age to start screening, the age to switch from cytology to HPV testing, HPV strategies not preceded by cytology, screening frequency, and management of HPV-positive/cytology-negative women.

RESULTS

We found that the current Swedish guidelines were more costly and less effective than alternative primary HPV-based strategies. All cost-efficient strategies involved primary HPV testing not preceded by cytology for younger women. Given a cost-effectiveness threshold of €85,619 per quality-adjusted life year gained, the optimal strategy involved 5-yearly primary HPV-based screening for women aged 23-50 years and 10-yearly HPV-based screening for women older than age 50 years.

CONCLUSIONS

Primary screening based on HPV alone may be considered for unvaccinated women for those countries with similar HPV burdens.

Reducing overtreatment associated with overdiagnosis in cervical cancer screening-A model-based benefit-harm analysis for Austria

A general concern exists that cervical cancer screening using human papillomavirus (HPV) testing may lead to considerable overtreatment. We evaluated the trade-off between benefits and overtreatment among different screening strategies differing by primary tests (cytology, p16/Ki-67, HPV alone or in combinations), interval, age and diagnostic follow-up algorithms. A Markov state-transition model calibrated to the Austrian epidemiological context was used to predict cervical cancer cases, deaths, overtreatments and incremental harm-benefit ratios (IHBR) for each strategy. When considering the same screening interval, HPV-based screening strategies were more effective compared to cytology or p16/Ki-67 testing (e.g., relative reduction in cervical cancer with biennial screening: 67.7% for HPV + Pap cotesting, 57.3% for cytology and 65.5% for p16/Ki-67), but were associated with increased overtreatment (e.g., 19.8% more conizations with biennial HPV + Papcotesting vs. biennial cytology). The IHBRs measured in unnecessary conizations per additional prevented cancer-related death were 31 (quinquennial Pap + p16/Ki-67-triage), 49 (triennial Pap + p16/Ki-67-triage), 58 (triennial HPV + Pap cotesting), 66 (biennial HPV + Pap cotesting), 189 (annual Pap + p16/Ki-67-triage) and 401 (annual p16/Ki-67 testing alone). The IHBRs increased significantly with increasing screening adherence rates and slightly with lower age at screening initiation, with a reduction in HPV incidence or with lower Pap-test sensitivity. Depending on the accepted IHBR threshold, biennial or triennial HPV-based screening in women as of age 30 and biennial cytology in younger women may be considered in opportunistic screening settings with low or moderate adherence such as in Austria. In organized settings with high screening adherence and in postvaccination settings with lower HPV prevalence, the interval may be prolonged.

The Cost-Effectiveness Analysis of Cervical Cancer Screening Using a Systematic Invitation System in Lithuania

In Lithuania, cytological screening of cervical cancer (CC) is largely opportunistic. Absence of standardized systematic invitation practice might be the reason for low participation rates. The study aimed to assess the cost-effectiveness of systematic invitation approach in CC screening programme from the perspective of a healthcare provider. A decision tree was used to compare an opportunistic invitation by a family doctor, a personal postal invitation letter with appointment time and place, and a personal postal invitation letter with appointment time and place with one reminder letter. Cost-effectiveness was defined as an incremental cost-effectiveness ratio (ICER) per one additionally screened woman and per one additional abnormal Pap smear test detected. The ICER of one personal postal invitation letter was €9.67 per one additionally screened woman and €55.21 per one additional abnormal Pap smear test detected in comparison with the current screening practice. The ICER of a personal invitation letter with an additional reminder letter compared to one invitation letter was €13.47 and €86.88 respectively. Conclusions: A personal invitation letter approach is more effective in increasing the participation rate in CC screening and the number of detected abnormal Pap smears; however, it incurs additional expenses compared with current invitation practice.

Prevention of cervical cancer in HIV-seropositive women from developing countries through cervical cancer screening: a systematic review

BACKGROUND

There is scanty or inconclusive evidence on which cervical cancer screening tool is effective and suitable for human immunodeficiency virus (HIV)-seropositive women. The aim of this review was to assess, synthesise and document published evidence relating to the available cervical cancer screening modalities for HIV-seropositive women in developing countries. This paper did not review the issue of human papillomavirus (HPV) prophylactic vaccine on HIV-seropositive women.

METHODS

Five electronic databases were systematically searched from inception to January 2018 for relevant published original research examining cervical cancer prevention modalities for HPV infection, abnormal cytology and direct visualisation of the cervix amongst HIV-seropositive women in developing countries. Extra studies were identified through reference list and citation tracking.

RESULTS

Due to methodological and clinical heterogeneity, a narrative synthesis was presented. Of the 2559 articles, 149 underwent full-text screening and 25 were included in the review. Included studies were of moderate quality, and no exclusions were made based on quality or bias. There is no standard cervical cancer screening test or programme for HIV-seropositive women and countries screening according to available resources and expertise. The screening methods used for HIV-seropositive women are the same for HIV-negative women, with varying clinical performance and accuracy. The main cervical cancer screening methods described for HIV-seropositive women are HPV deoxyribonucleic acid/messenger RNA (DNA/mRNA) testing (n = 16, 64.0%), visual inspection with acetic acid (VIA) (n = 13, 52.0%) and Pap smear (n = 11, 44.0%). HPV testing has a better accuracy/efficiency than other methods with a sensitivity of 80.0-97.0% and specificity of 51.0-78.0%. Sequential screening using VIA or visual inspection with Lugol's iodine (VILI) and HPV testing has shown better clinical performance in screening HIV-seropositive women.

CONCLUSION

Although cervical cancer screening exists in almost all developing countries, what is missing is both opportunistic and systematic organised population-based screenings. Cervical cancer screening programmes need to be integrated into already existing HIV services to enable early detection and treatment. There is a need to offer opportunistic and coordinated screening programmes that are provider-initiated to promote early identification of cervical precancerous lesions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018095702.

Cost-effective management of women with minor cervical lesions: Revisiting the application of HPV DNA testing

BACKGROUND

Lack of consensus in management guidelines for women with minor cervical lesions, coupled with novel screening approaches, such as human papillomavirus (HPV) genotyping, necessitate revisiting prevention policies. We evaluated the cost-effectiveness and resource trade-offs of alternative triage strategies to inform cervical cancer prevention in Norway.

METHODS

We used a decision-analytic model to compare the lifetime health and economic consequences associated with ten novel candidate approaches to triage women with minor cervical lesions. Candidate strategies varied by: 1) the triage test(s): HPV testing in combination with cytology, HPV testing alone with or without genotyping for HPV-16 and -18, and immediate colposcopy, and 2) the length of time between index and triage testing (i.e., 6, 12 or 18months). Model outcomes included quality-adjusted life-years (QALYs), lifetime societal costs, and resource use (e.g., colposcopy referrals).

RESULTS

The current Norwegian guidelines were less effective and more costly than candidate strategies. Given a commonly-cited willingness-to-pay threshold in Norway of $100,000 per QALY gained, the preferred strategy involved HPV genotyping with immediate colposcopy referral for HPV-16 or -18 positive and repeat HPV testing at 12months for non-HPV-16 or -18 positive ($78,010 per QALY gained). Differences in health benefits among candidate strategies were small, while resource use varied substantially. More effective strategies required a moderate increase in colposcopy referrals (e.g., a 9% increase for the preferred strategy) compared with current levels.

CONCLUSION

New applications of HPV testing may improve management of women with minor cervical lesions, yet are accompanied by a trade-off of increased follow-up procedures.

Using novel biomarkers to triage young adult women with minor cervical lesions: a cost-effectiveness analysis

OBJECTIVE

To evaluate the short-term consequences and cost-effectiveness associated with the use of novel biomarkers to triage young adult women with minor cervical cytological lesions.

DESIGN

Model-based economic evaluation using primary epidemiological data from Norway, supplemented with data from European and American clinical trials.

SETTING

Organised cervical cancer screening in Norway.

POPULATION

Women aged 25-33 years with minor cervical cytological lesions detected at their primary screening test.

METHODS

We expanded an existing simulation model to compare 12 triage strategies involving alternative biomarkers (i.e. reflex human papillomavirus (HPV) DNA/mRNA testing, genotyping, and dual staining) with the current Norwegian triage guidelines.

MAIN OUTCOME MEASURES

The number of high-grade precancers detected and resource use (e.g. monetary costs and colposcopy referrals) for a single screening round (3 years) for each triage strategy. Cost-efficiency, defined as the additional cost per additional precancer detected of each strategy compared with the next most costly strategy.

RESULTS

Five strategies were identified as cost-efficient, and are projected to increase the precancer detection rate between 18 and 57%, compared with current guidelines; however, the strategies did not uniformly require additional resources. Strategies involving HPV mRNA testing required fewer resources, whereas HPV DNA-based strategies detected >50% more precancers, but were more costly and required twice as many colposcopy referrals compared with the current guidelines.

CONCLUSION

Strategies involving biomarkers to triage younger women with minor cervical cytological lesions have the potential to detect additional precancers, yet the optimal strategy depends on the resources available as well as decision-makers' and women's acceptance of additional screening procedures.

TWEETABLE ABSTRACT

Women with minor cervical lesions may be triaged more accurately and effectively using novel biomarkers.