Cost-effectiveness of the conventional papanicolaou test with a new adjunct to cytological screening for squamous cell carcinoma of the uterine cervix and its precursors

Simple but not simpler: a systematic review of Markov models for economic evaluation of cervical cancer screening

The aim of this study was to critically evaluate the quality of the models used in economic evaluations of screening strategies for cervical cancer prevention. We systematically searched multiple databases, selecting model-based full economic evaluations (cost-effectiveness analyses, cost-utility analyses, and cost-benefit analyses) of cervical cancer screening strategies. Two independent reviewers screened articles for relevance and performed data extraction. Methodological assessment of the quality of the models utilized formal checklists, and a qualitative narrative synthesis was performed. Thirty-eight articles were reviewed. The majority of the studies were conducted in high-income countries (82%, n=31). The Pap test was the most used screening strategy investigated, which was present in 86% (n=33) of the studies. Half of the studies (n=19) used a previously published Markov model. The deterministic sensitivity analysis was performed in 92% (n=35) of the studies. The mean number of properly reported checklist items was 9 out of the maximum possible 18. Items that were better reported included the statement of decision problem, the description of the strategies/comparators, the statement of time horizon, and information regarding the disease states. Compliance with some items of the checklist was poor. The Markov models for economic evaluation of screening strategies for cervical cancer varied in quality. The following points require improvement: 1) assessment of methodological, structural, heterogeneity, and parameter uncertainties; 2) model type and cycle length justification; 3) methods to account for heterogeneity; and 4) report of consistency evaluation (through calibration and validation methods).

Systematic review of model-based cervical screening evaluations

BACKGROUND

Optimising population-based cervical screening policies is becoming more complex due to the expanding range of screening technologies available and the interplay with vaccine-induced changes in epidemiology. Mathematical models are increasingly being applied to assess the impact of cervical cancer screening strategies.

METHODS

We systematically reviewed MEDLINE®, Embase, Web of Science®, EconLit, Health Economic Evaluation Database, and The Cochrane Library databases in order to identify the mathematical models of human papillomavirus (HPV) infection and cervical cancer progression used to assess the effectiveness and/or cost-effectiveness of cervical cancer screening strategies. Key model features and conclusions relevant to decision-making were extracted.

RESULTS

We found 153 articles meeting our eligibility criteria published up to May 2013. Most studies (72/153) evaluated the introduction of a new screening technology, with particular focus on the comparison of HPV DNA testing and cytology (n = 58). Twenty-eight in forty of these analyses supported HPV DNA primary screening implementation. A few studies analysed more recent technologies - rapid HPV DNA testing (n = 3), HPV DNA self-sampling (n = 4), and genotyping (n = 1) - and were also supportive of their introduction. However, no study was found on emerging molecular markers and their potential utility in future screening programmes. Most evaluations (113/153) were based on models simulating aggregate groups of women at risk of cervical cancer over time without accounting for HPV infection transmission. Calibration to country-specific outcome data is becoming more common, but has not yet become standard practice.

CONCLUSIONS

Models of cervical screening are increasingly used, and allow extrapolation of trial data to project the population-level health and economic impact of different screening policy. However, post-vaccination analyses have rarely incorporated transmission dynamics. Model calibration to country-specific data is increasingly common in recent studies.

Basics of cytology

This overview is intended to give a general outline about the basics of Cytopathology. This is a field that is gaining tremendous momentum all over the world due to its speed, accuracy and cost effectiveness. This review will include a brief description about the history of cytology from its inception followed by recent developments. Discussion about the different types of specimens, whether exfoliative or aspiration will be presented with explanation of its rule as a screening and diagnostic test. A brief description of the indications, utilization, sensitivity, specificity, cost effectiveness, speed and accuracy will be carried out. The role that cytopathology plays in early detection of cancer will be emphasized. The ability to provide all types of ancillary studies necessary to make specific diagnosis that will dictate treatment protocols will be demonstrated. A brief description of the general rules of cytomorphology differentiating benign from malignant will be presented. Emphasis on communication between clinicians and pathologist will be underscored. The limitations and potential problems in the form of false positive and false negative will be briefly discussed. Few representative examples will be shown. A brief description of the different techniques in performing fine needle aspirations will be presented. General recommendation for the safest methods and hints to enhance the sensitivity of different sample procurement will be given. It is hoped that this review will benefit all practicing clinicians that may face certain diagnostic challenges requiring the use of cytological material.

A cost-effectiveness analysis of four management strategies in the determination and follow-up of atypical squamous cells of undetermined significance

Atypical squamous cells of undetermined significance (ASC-US) are the most common abnormal cytological result on Papanicolaou (Pap) smear. We analyzed four management strategies in a hypothetical cohort of women divided by age group: (1) immediate colposcopy, (2) repeat cytology after an ASC-US Pap smear result, (3) conventional Pap with reflex human papillomavirus (HPV) testing, and (4) liquid-based cytology with reflex HPV testing. Parameter variables were collected from previously published data. Strategies that included reflex HPV testing had the lowest overall costs for all age groups combined. Repeat Pap smears had the highest number of true positive results throughout all stages but also had the uppermost number of missed cancers and highest costs. Immediate colposcopy had the second highest overall costs and detected fewer true positive results than liquid-based cytology. Younger women (aged 18-24 yr) consistently had higher total costs for all strategies investigated. Using the incremental cost-effectiveness (CE) ratio, the immediate colposcopy strategy was more costly and less effective than liquid-based cytology and, therefore, was dominated. The incremental CE ratio was lowest for liquid-based cytology compared with conventional cytology and liquid-based cytology with reflex HPV testing was the most cost-effective strategy.

The health care costs of cervical human papillomavirus--related disease

OBJECTIVE

The purpose of this study was to examine the health care costs of cervical human papillomavirus-related disease in a US health care setting.

STUDY DESIGN

We conducted an observational cohort study using 1997 through 2002 administrative and laboratory records from 103,476 female enrollees of the Kaiser Permanente Northwest health plan (Portland, Ore). We examined the cost per case and annual cost per 1000 enrollees for cervical human papillomavirus-related events.

RESULTS

A cervical examination with a normal routine papanicolaou smear incurred costs of 57 dollars (95% CI, 57-57). Costs that were associated with abnormal routine screening diagnoses ranged from 299 dollars for atypical squamous cells (95% CI, 245-352) to 2349 dollars for high-grade squamous intraepithelial lesion (95% CI, 1,047-3,650). The costs of histologically confirmed cervical intraepithelial neoplasia ranged from 1026 dollars for cervical intraepithelial neoplasia 1 (95% CI, 862-1191) to 3235 dollars for cervical intraepithelial neoplasia 3 (95% CI, 2051-4419); a cost of 376 dollars (95% CI, 315-436) was associated with false-positive test results. At the level of the health plan, overall annual cervical cancer prevention and treatment costs were 26,415 dollars per 1000 female enrollees, with routine cervical cancer screening accounting for expenditures of 16,746 dollars per 1000 female enrollees, cervical intraepithelial neoplasia accounting for expenditures of 4535 dollars per 1000 female enrollees, cervical cancer accounting for expenditures of 2629 dollars per 1000 female enrollees, and false-positive test results accounting for expenditures of 2394 dollars per 1000 female enrollees.

CONCLUSION

These are the first direct estimates of both individual and population level costs of cervical human papillomavirus-related disease in a general US health care setting. Routine cervical cancer screening comprises nearly two thirds of total annual cervical human papillomavirus-related health care costs, with 10% of expenditures dedicated to the treatment of invasive cervical cancer, 17% to the management of cervical precancers, and 9% to dealing with false-positive Papanicolaou test results.

Cost-effectiveness analyses in gynecologic oncology: methodological quality and trends

OBJECTIVES

To evaluate methodological quality and trends of cost-effectiveness analyses (CEA) published in gynecologic oncology.

METHODS

A medical literature search of articles from 1966 through 2002 was performed to identify original, English-language articles that included economic analyses in gynecologic oncology. We included articles that were cost-effectiveness or cost-benefit analyses or performed these analyses as part of their study. Ten methodological principles that should be incorporated in CEAs were assessed for each study. Each article was given a score of 0, 1, or 2 for each of the 10 methodological principles (max score = 20). Data were analyzed using the Student t test, ANOVA, and linear regression.

RESULTS

We screened 693 articles to identify 68 that met our inclusion criteria. The articles focused on cervical cancer (n = 53; 78%), ovarian cancer (n = 11; 16%), uterine cancer (n = 2; 3%), and general perioperative care (n = 2; 3%). The mean (+/-SD) methodological principle score was 16.1 (+/-4.1) and we observed a significant improvement in the total score over time (P = 0.01). Primary CEA's (CEA identified as the objective of the study) were of higher quality than secondary CEA's (primary objective of the study was not CEA but CEA was included in the study; total scores 18.2 vs. 11.6, respectively; P<0.0001). Studies with at least one investigator in public health or healthcare economies also had higher quality (mean total score 17.7 vs. 15.2; P=0.006). The most common limitations of published CEAs were in methodology or presentation of incremental analyses, sensitivity analyses, and discounting.

CONCLUSIONS

Cost-effectiveness analyses in gynecologic oncology showed significant improvement in quality over the last two decades. Despite this progress, methodological improvement is still needed in the areas of incremental comparisons and sensitivity analysis. Understanding the methodology of cost-effectiveness analysis is critical for researchers, editors, and readers to accurately interpret results of the growing body of CEA articles.

What is the least costly strategy to evaluate cervical abnormalities in rural women? Comparing telemedicine, local practitioners, and expert physicians

OBJECTIVE

This study establishes the least costly strategy for evaluation of rural women in need of colposcopy among 3 alternatives: telemedicine, local practitioners, and referral experts.

METHODS

Women in rural Georgia who needed colposcopy were examined by an expert colposcopist on site, by a local practitioner, and by a distant expert colposcopist linked by telemedicine. Independent determinations of biopsy intent were used to model the differing biopsy costs of the 3 methods. Record review determined the average total cost of telemedicine. Reports of average cost in year 2000 dollars from societal perspective include medical costs and pain and suffering due to additional biopsies and curettage, telemedicine costs, and costs of potential diagnostic delay for a 1-year time horizon.

RESULTS

From the societal perspective in the baseline case, the average cost per patient evaluated was dollar 270 for patients seen by referral experts. The cost was dollar 38 less (e.g., dollar 232) for patients seen by local practitioners, and dollar 35 more (e.g., dollar 305) for patients seen by telemedicine. From the societal perspective, local practitioners were less costly than referral experts because of lower travel costs for patients, but from the medical perspective, their average cost was dollar 32 higher than referral experts because they performed more biopsies and curettage procedures than experts. Telemedicine assistance would have lowered the number of biopsies performed by local practitioners, but as of year 2000 the costs of this technology could not be justified by the savings.

CONCLUSION

From the societal perspective, local practitioners performing colposcopy are the least costly way to evaluate cervical abnormalities in rural patients with substantial time and travel costs.

Chapter 15: Public health policy and cost-effectiveness analysis

Recent scientific advances are providing an opportunity to revisit strategies for cervical cancer prevention. How to invest health resources wisely, such that public health benefits are maximized-and opportunity costs are minimized-is a critical question in the setting of enhanced cytologic screening methods, human papillomavirus DNA testing, and vaccine development. Developing sound clinical guidelines and public health policy will require careful consideration of the incremental benefits, harms, and costs associated with new interventions compared with existing interventions, at both an individual and a population level. In addition to an intervention's effectiveness, public health decision making requires the consideration of its feasibility, sustainability, and affordability. No clinical trial or single cohort study will be able to simultaneously consider all of these components. Cost-effectiveness analysis and disease-simulation modeling, capitalizing on data from multiple sources, can serve as a valuable tool to extend the time horizon of clinical trials, to evaluate more strategies than possible in a single clinical trial, and to assess the relative costs and benefits of alternative policies to reduce mortality from cervical cancer.

Cost-effectiveness of a potential vaccine for human papillomavirus

Human papillomavirus (HPV) infection, usually a sexually transmitted disease, is a risk factor for cervical cancer. Given the substantial disease and death associated with HPV and cervical cancer, development of a prophylactic HPV vaccine is a public health priority. We evaluated the cost-effectiveness of vaccinating adolescent girls for high-risk HPV infections relative to current practice. A vaccine with a 75% probability of immunity against high-risk HPV infection resulted in a life-expectancy gain of 2.8 days or 4.0 quality-adjusted life days at a cost of $246 relative to current practice (incremental cost effectiveness of $22,755/quality-adjusted life year [QALY]). If all 12-year-old girls currently living in the United States were vaccinated, >1,300 deaths from cervical cancer would be averted during their lifetimes. Vaccination of girls against high-risk HPV is relatively cost effective even when vaccine efficacy is low. If the vaccine efficacy rate is 35%, the cost effectiveness increases to $52,398/QALY. Although gains in life expectancy may be modest at the individual level, population benefits are substantial.

Paying for prevention standardizing the measurement of the value of health care interventions

It is not clear if spending more on tests that enhance the accuracy of Pap smears would lead to a greater reduction in cancer incidence than if the money were spent to include a greater proportion of women in primary screening. The cost effectiveness of tests beyond the Pap smear has not been clearly demonstrated. There is the question of whether cervical cancer incidence can be decreased more by improving the tests for patients who are already screened or by improving access to the unscreened population. Cervical cancer screening represents only one of many public health issues competing for resources. Given that there are choices to be made, the optimal yardstick against which all resource-competing programs are measured should be marginal benefit versus marginal cost.