Cost-effectiveness of partner pharmacotherapy in screening women for asymptomatic infection with Chlamydia Trachomatis

A Web-Based Sexual Health Intervention to Prevent Sexually Transmitted Infections in Hong Kong: Model-Based Cost-Effectiveness Analysis

BACKGROUND

Sexually transmitted infections (STIs) remain a significant public health concern, particularly among young adults, and Chlamydia trachomatis (CT) infections are the most common STIs in young women. One of the most effective ways to prevent STIs is the consistent use of condoms during sexual intercourse. There has been no economic evaluation of the interactive web-based sexual health program, Smart Girlfriend, within the Chinese population.

OBJECTIVE

This study aimed to evaluate the long-term cost-effectiveness of Smart Girlfriend in preventing STIs in the Chinese population. The evaluation compared the program with a control intervention that used a 1-page information sheet on condom use.

METHODS

A decision-analytic model that included a decision tree followed by a Markov structure of CT infections was developed since CT is the most prevalent STI among young women. The model represents the long-term experience of individuals who received either the intervention or the control. One-way and probabilistic sensitivity analyses were conducted. The main outcomes were the number of CT infections and the incremental cost as per quality-adjusted life year (QALY).

RESULTS

A cohort of 10,000 sexually active nonpregnant young women initially entered the model in a noninfectious state (ie, "well"). In the base-case analysis, the implementation of the Smart Girlfriend program resulted in the prevention of 0.45% of CT infections, 0.3% of pelvic inflammatory disease, and 0.04% of chronic pelvic pain, leading to a gain of 70 discounted QALYs and cost savings over a 4-year time horizon, compared to the control group. With more than 4548 users, the intervention would be cost-effective, and with more than 8315 users, the intervention would be cost saving. A 99% probability of being cost-effective was detected with a willingness to pay US $17,409 per QALY.

CONCLUSIONS

Smart Girlfriend is a cost-effective and possibly cost-saving program over a 4-year time horizon. This result was particularly sensitive to the number of website users; launching the website would be cost-effective if more than 4548 people used it. Further work is warranted to explore if the findings could be expanded to apply to women who have sex with women and in the context of other STIs.

TRIAL REGISTRATION

ClinicalTrial.gov NCT03695679; https://clinicaltrials.gov/study/NCT03695679.

Cost-effectiveness analysis of Chlamydia trachomatis screening in Dutch pregnant women

Chlamydia trachomatis infections during pregnancy may have serious consequences for women and their offspring. Chlamydial infections are largely asymptomatic. Hence, prevention is based on screening. The objective of this study was to estimate the cost-effectiveness of C. trachomatis screening during pregnancy. We used a health-economic decision analysis model, which included potential health outcomes of C. trachomatis infection for women, partners and infants, and premature delivery. We estimated the cost-effectiveness from a societal perspective using recent prevalence data from a population-based prospective cohort study among pregnant women in the Netherlands. We calculated the averted costs by linking health outcomes with health care costs and productivity losses. Cost-effectiveness was expressed as net costs per major outcome prevented and was estimated in base-case analysis, sensitivity, and scenario analysis. In the base-case analysis, the costs to detect 1000 pregnant women with C. trachomatis were estimated at €527,900. Prevention of adverse health outcomes averted €626,800 in medical costs, resulting in net cost savings. Sensitivity analysis showed that net cost savings remained with test costs up to €22 (test price €19) for a broad range of variation in underlying assumptions. Scenario analysis showed even more cost savings with targeted screening for women less than 30 years of age or with first pregnancies only. Antenatal screening for C. trachomatis is a cost-saving intervention when testing all pregnant women in the Netherlands. Savings increase even further when testing women younger than 30 years of age or with pregnancies only.

Chlamydia sequelae cost estimates used in current economic evaluations: does one-size-fit-all?

BACKGROUND

Current evidence suggests that chlamydia screening programmes can be cost-effective, conditional on assumptions within mathematical models. We explored differences in cost estimates used in published economic evaluations of chlamydia screening from seven countries (four papers each from UK and the Netherlands, two each from Sweden and Australia, and one each from Ireland, Canada and Denmark).

METHODS

From these studies, we extracted management cost estimates for seven major chlamydia sequelae. In order to compare the influence of different sequelae considered in each paper and their corresponding management costs on the total cost per case of untreated chlamydia, we applied reported unit sequelae management costs considered in each paper to a set of untreated infection to sequela progression probabilities. All costs were adjusted to 2013/2014 Great British Pound (GBP) values.

RESULTS

Sequelae management costs ranged from £171 to £3635 (pelvic inflammatory disease); £953 to £3615 (ectopic pregnancy); £546 to £6752 (tubal factor infertility); £159 to £3341 (chronic pelvic pain); £22 to £1008 (epididymitis); £11 to £1459 (neonatal conjunctivitis) and £433 to £3992 (neonatal pneumonia). Total cost of sequelae per case of untreated chlamydia ranged from £37 to £412.

CONCLUSIONS

There was substantial variation in cost per case of chlamydia sequelae used in published chlamydia screening economic evaluations, which likely arose from different assumptions about disease management pathways and the country perspectives taken. In light of this, when interpreting these studies, the reader should be satisfied that the cost estimates used sufficiently reflect the perspective taken and current disease management for their respective context.

Sexually transmitted infections screening at HIV treatment centers for MSM can be cost-effective

OBJECTIVE

To estimate the cost-effectiveness of anorectal chlamydia screening among men who have sex with men (MSM) in care at HIV treatment centers.

DESIGN

Transmission model combined with economic analysis over a 20-year period.

SETTING AND PARTICIPANTS

MSM in care at HIV treatment centers.

INTERVENTION

Once-yearly or twice-yearly screening for anorectal chlamydia among MSM in care at HIV treatment centers.

MAIN OUTCOME MEASURES

Averted HIV and chlamydia infections; discounted quality-adjusted life-years and costs; incremental cost-effectiveness ratio (ICER).

RESULTS

Costs will be saved by routine chlamydia screening of MSM in care at HIV treatment centers if these patients seek little or no screening elsewhere. Nonroutine screening is considerably more expensive than routine screening offered within a scheduled visit. Adding once-yearly chlamydia screening for MSM in care at HIV treatment centers is cost saving when 30% or fewer of those men seek once-yearly screening elsewhere (1.5 to 8.1 million euro saved). Twice-yearly routine screening at HIV treatment centers is cost-effective only when routine screening takes place without additional nonroutine screening (1.9 million euro saved).

CONCLUSIONS

Adding annual chlamydia screening to the HIV consultation will be cost saving as long as only a limited proportion of men are nonroutinely screened. The ICER was most sensitive to the percentage of MSM that continue to be screened elsewhere.

Development and Evaluation of GIS-Based Chlamydia Trachomatis Intervention Policy in Illinois

Chlamydia trachomatis is the most prevalent infectious disease in the United States. Complications include pelvic inflammatory disease (PID), ectopic pregnancy, and infertility. The cost of PID in 1998 was estimated at greater than $1.9 billion. Screening intervention strategies are often consumed by those at low risk. The objective of this study is the development of a more cost-effective intervention strategy by employing Geographic Information Systems and Census Bureau demographic data in selected Local Health Departments in Illinois. Case studies of intervention activities at the state and local level were performed. An evaluability assessment model of current inputs, processes and outcomes was created. A proposed model utilizing additional state inputs was developed and tested. Interventions were evaluated for effectiveness in reducing the incidence of Chlamydia trachomatis. Societal cost effectiveness analysis was also performed. The proposed model was tested in 2006. Results indicate that only minimal changes in annual incidence are required for GIS-augmented interventions to be cost-effective.

Management of uncomplicated Chlamydia trachomatis infections in adolescents and adults: evidence reviewed for the 2006 Centers for Disease Control and Prevention sexually transmitted diseases treatment guidelines

In April 2005, in preparation for the 2006 Centers for Disease Control and Prevention (CDC) sexually transmitted diseases (STD) treatment guidelines, the CDC convened an advisory group to examine recent abstracts and published literature addressing management of Chlamydia trachomatis infections in adolescents and adults. Key questions were posed and answered on the basis of quality of evidence and expert opinion. Clinical trials continue to demonstrate equivalent efficacy and tolerability of azithromycin and doxycycline regimens, and both remain recommended as first-line therapy in nonpregnant individuals. More data and clinical experience are available to support the efficacy, safety, and tolerability of azithromycin in pregnant women, and, in the upcoming guidelines, azithromycin will be recommended as first-line therapy for such patients. Evidence is building that expedited partner therapy (EPT), with provision of treatment or a prescription, may be just as effective as or more effective than standard partner referral in ensuring partner treatment and preventing chlamydia recurrence in women. Although there are more studies needed and barriers to be addressed before its widespread use, EPT will be recommended as an option for partner management.

One to one interventions to reduce sexually transmitted infections and under the age of 18 conceptions: a systematic review of the economic evaluations

OBJECTIVE

To systematically review and critically appraise the economic evaluations of one to one interventions to reduce sexually transmitted infections (STIs) and teenage conceptions.

DESIGN

Systematic review.

DATA SOURCES

Search of four electronic bibliographic databases from 1990 to January 2006. Search keywords included teenage, pregnancy, adolescent, unplanned, unwanted, cost benefit, cost utility, economic evaluation, cost effectiveness and all terms for STIs, including specific diseases.

REVIEW METHODS

We included studies that evaluated a broad range of one to one interventions to reduce STIs. Outcomes included major outcomes averted, life years and quality adjusted life years (QALY). All studies were assessed against quality criteria.

RESULTS

Of 3,190 identified papers, 55 were included. The majority of studies found one to one interventions to be either cost saving or cost effective, although one highlighted the need to target the population to receive post-exposure prophylaxis to reduce transmission of HIV. Most studies used a static approach that ignores the potential re-infection of treated patients.

CONCLUSION

One to one interventions have been shown to be cost saving or cost effective but there are some limitations in applying this evidence to the UK policy context. More UK research using dynamic modelling approaches and QALYs would provide improved evidence, enabling more robust policy recommendations to be made about which one to one interventions are cost effective in reducing STIs in the UK setting. The results of this review can be used by policy makers, health economists and researchers considering further research in this area.

Screening for Chlamydia trachomatis: a systematic review of the economic evaluations and modelling

OBJECTIVE

To review systematically and critically, evidence used to derive estimates of costs and cost effectiveness of chlamydia screening.

METHODS

Systematic review. A search of 11 electronic bibliographic databases from the earliest date available to August 2004 using keywords including chlamydia, pelvic inflammatory disease, economic evaluation, and cost. We included studies of chlamydia screening in males and/or females over 14 years, including studies of diagnostic tests, contact tracing, and treatment as part of a screening programme. Outcomes included cases of chlamydia identified and major outcomes averted. We assessed methodological quality and the modelling approach used.

RESULTS

Of 713 identified papers we included 57 formal economic evaluations and two cost studies. Most studies found chlamydia screening to be cost effective, partner notification to be an effective adjunct, and testing with nucleic acid amplification tests, and treatment with azithromycin to be cost effective. Methodological problems limited the validity of these findings: most studies used static models that are inappropriate for infectious diseases; restricted outcomes were used as a basis for policy recommendations; and high estimates of the probability of chlamydia associated complications might have overestimated cost effectiveness. Two high quality dynamic modelling studies found opportunistic screening to be cost effective but poor reporting or uncertainty about complication rates make interpretation difficult.

CONCLUSION

The inappropriate use of static models to study interventions to prevent a communicable disease means that uncertainty remains about whether chlamydia screening programmes are cost effective or not. The results of this review can be used by health service managers in the allocation of resources, and health economists and other researchers who are considering further research in this area.

Systematic screening for Chlamydia trachomatis: estimating cost-effectiveness using dynamic modeling and Dutch data

OBJECTIVE

To estimate the cost-effectiveness of a systematic one-off Chlamydia trachomatis (CT) screening program including partner treatment for Dutch young adults.

METHODS

Data on infection prevalence, participation rates, and sexual behavior were obtained from a large pilot study conducted in The Netherlands. Opposite to almost all previous economic evaluations of CT screening, we developed a dynamic Susceptible-Infected-Susceptible (SIS) model to estimate the impact of the screening program on the incidence and prevalence of CT in the population. SIS models are widely used in epidemiology of infectious diseases, for modeling the transmission dynamics over time. Subsequently, a predictive decision model was used to calculate the complications averted by the screening program. Cost-effectiveness was expressed as the net costs per major outcome averted (MOA) and was estimated in the baseline analysis and in sensitivity analysis.

RESULTS

The overall prevalence decreased from 1.79% to 1.05% as a result of the screening program directed at both men and women. The program costs were mainly offset by the averted costs, although not fully. Resulting net costs per MOA were 373 euro sin the baseline analysis. Sensitivity analysis showed that partner treatment and sending a reminder are important aspects improving cost-effectiveness. Additionally, restricting the screening to women only was estimated to save costs.

CONCLUSIONS

Our cost-effectiveness analysis shows that the Dutch society has net to pay for the prevention of CT-complications through screening young men and women. One could argue although that 373 euros per MOA presents a reasonable cost. A screening program consisting of screening women only should always be adopted from a pharmacoeconomic point of view. Our dynamic approach appreciates better the specific characteristics of an infectious disease, such as CT.

Adherence of Pharmacoeconomic Studies to National Guidelines in the Netherlands

OBJECTIVE

This study examines the adherence of Dutch pharmacoeconomic studies to the national guidelines of conducting a pharmacoeconomic evaluation.

METHODS

Dutch guidelines for pharmacoeconomic research were issued in 1999. All Dutch pharmacoeconomic studies that were published in English during 2000-2002 were selected for our review. Two reviewers examined each study for relevance and compared each study with the nine methodological guidelines selected.

RESULTS

It was found that 29 studies satisfied the inclusion criteria. The societal perspective was taken in 13 out of the 29 studies (45%), an adequate time period of analysis was chosen in 21 (72%), effectiveness was explicitly differentiated from efficacy in 17 (59%), an incremental analysis was performed in 23 (79%), costs, benefits and health gains were discounted in 24 (83%), effectiveness was expressed in LYGs or QALYs in 16 (55%), reference prices were used in 8 (28%), subgroup analysis was presented in 13 (45%) and sensitivity analysis was included in 26 (90%).

CONCLUSIONS

In this review we found that the adherence of studies to some of the Dutch guidelines for pharmacoeconomic studies is fair. However, major improvements are required with respect to the adoption of the societal perspective, presentation of adequate subgroup analyses and application of reference prices.

Modelling the healthcare costs of an opportunistic chlamydia screening programme

OBJECTIVES

To estimate the average cost per screening offer, cost per testing episode and cost per chlamydia positive episode for an opportunistic chlamydia screening programme (including partner management), and to explore the uncertainty of parameter assumptions, based on the costs to the healthcare system.

METHODS

A decision tree was constructed and parameterised using empirical data from a chlamydia screening pilot study and other sources. The model was run using baseline data from the pilot, and univariate and multivariate sensitivity analyses were conducted.

RESULTS

The total estimated cost for offering screening over 12 months to 33,215 females aged 16-24 was 493,412 pounds . The average cost (with partner management) was 14.88 pounds per screening offer (90% credibility interval (CI) 10.34 to 18.56), 21.83 pounds per testing episode (90% CI 18.16 to 24.20), and 38.36 pounds per positive episode (90% CI 33.97 to 42.25). The proportion of individuals accepting screening, the clinician (general practitioner/nurse) time and their relative involvement in discussing screening, the test cost, the time to notify patients of their results, and the receptionist time recruiting patients had the greatest impact on the outcomes in both the univariate and multivariate sensitivity analyses.

CONCLUSIONS

Results from this costing study may be used to inform resource allocation for current and future chlamydia screening programme implementation.

A refined estimate of the average lifetime cost of pelvic inflammatory disease

BACKGROUND

The major complications of pelvic inflammatory disease (infertility, ectopic pregnancy, and chronic pelvic pain) are the leading cause of non-HIV sexually transmitted disease morbidity in the United States.

GOAL

The goal of the study was to estimate a plausible range for the average lifetime cost of pelvic inflammatory disease (PID) and its major complications in a cohort of U.S. women of reproductive age.

STUDY DESIGN

We developed a state-transition computer-based model to simulate the natural history of PID, incorporating the severity of infection, number of recurrent episodes, treatment setting, and the risk over time of major complications. Clinical and cost data were from the published literature. Model outcomes included life expectancy, quality-adjusted life expectancy, and lifetime costs.

RESULTS

In a cohort of 100,000 females acquiring PID between 20 and 24 years of age, 8550 ectopic pregnancies, 16,800 cases of infertility, and 18,600 cases of chronic pelvic pain were projected to occur. Assuming a 3% annual discount rate, we found the average per-person lifetime cost to be $2150. Average lifetime costs for women who developed major complications were $6350 for chronic pelvic pain, $6840 for ectopic pregnancy, and $1270 for infertility. The majority of costs (79%) were accrued within 5 years of upper genital tract infection. Results were most sensitive to assumptions about the timing of major complications and the discount rate.

CONCLUSION

The average per-person lifetime cost of PID ranges between $1060 and $3180. Future cost-effectiveness analyses of STD screening programs can include this range as a reasonable upper and lower bound. These findings suggest successful PID prevention efforts may avert substantial costs for care providers such as managed care organizations while providing well documented clinical benefits for women in the United States.