A systematic literature review of cardiovascular event utilities

International Systematic Review of Utility Values Associated with Cardiovascular Disease and Reflections on Selecting Evidence for a UK Decision-Analytic Model

PURPOSE

Evaluating interventions for cardiovascular disease (CVD) requires estimates of its effect on utility. We aimed to 1) systematically review utility estimates for CVDs published since 2013 and 2) critically appraise UK-relevant estimates and calculate corresponding baseline utility multipliers.

METHODS

We searched MEDLINE and Embase (April 22, 2021) using CVD and utility terms. We screened results for primary studies reporting utility distributions for people with experience of heart failure, myocardial infarction, peripheral arterial disease, stable angina, stroke, transient ischemic attack, or unstable angina. We extracted characteristics from studies included. For UK estimates based on the EuroQoL 5-dimension (EQ-5D) measure, we assessed risk of bias and applicability to a decision-analytic model, pooled arms/time points as appropriate, and estimated baseline utility multipliers using predicted utility for age- and sex- matched populations without CVD. We sought utility sources from directly applicable studies with low risk of bias, prioritizing plausibility of severity ordering in our base-case model and highest population ascertainment in a sensitivity analysis.

RESULTS

Most of the 403 studies identified used EQ-5D (n = 217) and most assessed Organisation for Economic Co-operation and Development populations (n = 262), although measures and countries varied widely. UK studies using EQ-5D (n = 29) produced very heterogeneous baseline utility multipliers for each type of CVD, precluding meta-analysis and implying different possible severity orderings. We could find sources that provided a plausible ordering of utilities while adequately representing health states.

CONCLUSIONS

We cataloged international CVD utility estimates and calculated UK-relevant baseline utility multipliers. Modelers should consider unreported sources of heterogeneity, such as population differences, when selecting utility evidence from reviews.

HIGHLIGHTS

Published systematic reviews have summarized estimates of utility associated with cardiovascular disease published up to 2013.We 1) reviewed utility estimates for 7 types of cardiovascular disease published since 2013, 2) critically appraised UK-relevant studies, and 3) estimated the effect of each cardiovascular disease on baseline utility.Our review 1) recommends a consistent and reliable set of baseline utility multipliers for 7 types of cardiovascular disease and 2) provides systematically identified reference information for researchers seeking utility evidence for their own context.

The cost-effectiveness of a uniform versus age-based threshold for one-off screening for prevention of cardiovascular disease

The objective of this article was to assess the cost-effectiveness of screening strategies for cardiovascular diseases (CVD). A decision analytic model was constructed to estimate the costs and benefits of one-off screening strategies differentiated by screening age, sex and the threshold for initiating statin therapy ("uniform" or "age-adjusted") from the Spanish NHS perspective. The age-adjusted thresholds were configured so that the same number of people at high risk would be treated as under the uniform threshold. Health benefit was measured in quality-adjusted life years (QALY). Transition rates were estimated from the European Prospective Investigation into Cancer and Nutrition (EPIC-CVD), a large multicentre nested case-cohort study with 12 years of follow-up. Unit costs of primary care, hospitalizations and CVD care were taken from the Spanish health system. Univariate and probabilistic sensitivity analyses were employed. The comparator was no systematic screening program. The base case model showed that the most efficient one-off strategy is to screen both men and women at 40 years old using a uniform risk threshold for initiating statin treatment (Incremental Cost-Effectiveness Ratio of €3,274/QALY and €6,085/QALY for men and women, respectively). Re-allocating statin treatment towards younger individuals at high risk for their age and sex would not offset the benefit obtained using those same resources to treat older individuals. Results are sensitive to assumptions about CVD incidence rates. To conclude, one-off screening for CVD using a uniform risk threshold appears cost-effective compared with no systematic screening. These results should be evaluated in clinical studies.

Impact of Atopic Dermatitis and Chronic Hand Eczema on Quality of Life Compared With Other Chronic Diseases

: The aim of this study was to conduct 3 literature reviews to examine the impact of atopic dermatitis (AD) and chronic hand eczema (CHE) on health-related quality of life (HRQoL) compared with other chronic conditions by comparing reported utility scores of 4 commonly used generic HRQoL instruments. A systematic search was performed using PubMed, ScienceDirect, MEDLINE, EMBASE, Health Technology Assessment database, and ScHARRHUD. Inclusion criteria included, but were not limited to, patients of any age, studies from any location, publications reporting utility data based on EuroQoL 5 dimensions, the EuroQoL 5-dimension Visual Analog Scale, the Short-Form Health Survey, and the Short-Form 6 Dimensions in the English language. Inclusion criteria were met by 16 articles for AD, 25 articles for chronic conditions, and 9 articles for CHE. The findings of this review highlight that the disutility and loss in HRQoL of patients with AD and CHE are similar to or higher than other chronic conditions, such as cancer or hepatitis.

Utility value estimates in cardiovascular disease and the effect of changing elicitation methods: a systematic literature review

OBJECTIVE

Identify the most recent utility value estimates for cardiovascular disease (CVD) via systematic literature review (SLR) and explore trends in utility elicitation methods in the last 6 years.

METHODS

This SLR was updated on January 25, 2018, and identified studies reporting utilities for myocardial infarction (MI), stroke, angina, peripheral artery disease (PAD), and any-cause revascularization by searching Embase, PubMed, Health Technology Assessment Database, and grey literature.

RESULTS

A total of 375 studies reported CVD utilities (pre-2013 vs post-2013: MI, 38 vs 32; stroke, 86 vs 113; stable angina, 8 vs 9; undefined/unstable angina, 23 vs 8; PAD, 29 vs 13; revascularization, 54 vs 40). Median average utilities for MI, stroke, and revascularization increased over time (pre-2013 vs post-2013: MI, 0.71 vs 0.79; stroke, 0.63 vs 0.64; revascularization, 0.76 vs 0.81); angina and PAD showed a decrease in median values over time (stable angina, 0.83 vs 0.72; undefined/unstable angina, 0.70 vs 0.69; PAD, 0.76 vs 0.71). The proportion of utility estimates from trials increased across health states (pre-2013 vs post-2013: 22.5% vs 37.2%), as did the proportion of trials using the EuroQol Five Dimensions Questionnaire (EQ-5D; pre-2013 vs post-2013: 73.8% vs 91.4%). Use of methods such as the standard gamble, time trade-off, and Health Utilities Index has declined.

CONCLUSIONS

Health state utilities for cardiovascular health states have changed in the last 6 years, likely due to changes in the types of studies conducted, the patient populations evaluated, and possibly changing utility elicitation methods. The EQ-5D has been used more frequently.

Implantable cardiac monitors to detect atrial fibrillation after cryptogenic stroke: a systematic review and economic evaluation

BACKGROUND

Cryptogenic stroke is a stroke for which no cause is identified after standard diagnostic tests. Long-term implantable cardiac monitors may be better at diagnosing atrial fibrillation and provide an opportunity to reduce the risk of stroke recurrence with anticoagulants.

OBJECTIVES

The objectives were to assess the diagnostic test accuracy, clinical effectiveness and cost-effectiveness of three implantable monitors [BioMonitor 2-AF™ (Biotronik SE & Co. KG, Berlin, Germany), Confirm Rx™ (Abbott Laboratories, Lake Bluff, IL, USA) and Reveal LINQ™ (Medtronic plc, Minneapolis, MN, USA)] in patients who have had a cryptogenic stroke and for whom no atrial fibrillation is detected after 24 hours of external electrocardiographic monitoring.

DATA SOURCES

MEDLINE, EMBASE, The Cochrane Library, Database of Abstracts of Reviews of Effects and Health Technology Assessment databases were searched from inception until September 2018.

REVIEW METHODS

A systematic review was undertaken. Two reviewers agreed on studies for inclusion and performed quality assessment using the Cochrane Risk of Bias 2.0 tool. Results were discussed narratively because there were insufficient data for synthesis. A two-stage de novo economic model was developed: (1) a short-term patient flow model to identify cryptogenic stroke patients who have had atrial fibrillation detected and been prescribed anticoagulation treatment (rather than remaining on antiplatelet treatment) and (2) a long-term Markov model that captured the lifetime costs and benefits of patients on either anticoagulation or antiplatelet treatment.

RESULTS

One randomised controlled trial, Cryptogenic Stroke and underlying Atrial Fibrillation (CRYSTAL-AF) (Sanna T, Diener HC, Passman RS, Di Lazzaro V, Bernstein RA, Morillo CA, et al. Cryptogenic stroke and underlying atrial fibrillation. N Engl J Med 2014;370:2478-86), was identified, and no diagnostic test accuracy study was identified. The CRYSTAL-AF trial compared the Reveal™ XT (a Reveal LINQ predecessor) (Medtronic plc) monitor with standard of care monitoring. Twenty-six single-arm observational studies for the Reveal devices were also identified. The only data for BioMonitor 2-AF or Confirm Rx were from mixed population studies supplied by the companies. Atrial fibrillation detection in the CRYSTAL-AF trial was higher with the Reveal XT than with standard monitoring at all time points. By 36 months, atrial fibrillation was detected in 19% of patients with an implantable cardiac monitor and in 2.3% of patients receiving conventional follow-up. The 26 observational studies demonstrated that, even in a cryptogenic stroke population, atrial fibrillation detection rates are highly variable and most cases are asymptomatic; therefore, they probably would not have been picked up without an implantable cardiac monitor. Device-related adverse events, such as pain and infection, were low in all studies. The de novo economic model produced incremental cost effectiveness ratios comparing implantable cardiac monitors with standard of care monitoring to detect atrial fibrillation in cryptogenic stroke patients based on data for the Reveal XT device, which can be related to Reveal LINQ. The BioMonitor 2-AF and Confirm RX were included in the analysis by making a strong assumption of equivalence with Reveal LINQ. The results indicate that implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold. When each device is compared incrementally, BioMonitor 2-AF dominates Reveal LINQ and Confirm RX.

LIMITATIONS

The cost-effectiveness analysis for implantable cardiac monitors is based on a strong assumption of clinical equivalence and should be interpreted with caution.

CONCLUSIONS

All three implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold, compared with standard of care monitoring, for cryptogenic stroke patients with no atrial fibrillation detected after 24 hours of external electrocardiographic monitoring; however, further clinical studies are required to confirm their efficacy in cryptogenic stroke patients.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42018109216.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 5. See the NIHR Journals Library website for further project information.

Economic impact of potentially inappropriate prescribing and related adverse events in older people: a cost-utility analysis using Markov models

OBJECTIVES

To determine the economic impact of three drugs commonly involved in potentially inappropriate prescribing (PIP) in adults aged ≥65 years, including their adverse effects (AEs): long-term use of non-steroidal anti-inflammatory drugs (NSAIDs), benzodiazepines and proton pump inhibitors (PPIs) at maximal dose; to assess cost-effectiveness of potential interventions to reduce PIP of each drug.

DESIGN

Cost-utility analysis. We developed Markov models incorporating the AEs of each PIP, populated with published estimates of probabilities, health system costs (in 2014 euro) and utilities.

PARTICIPANTS

A hypothetical cohort of 65 year olds analysed over 35 1-year cycles with discounting at 5% per year.

OUTCOME MEASURES

Incremental cost, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios with 95% credible intervals (CIs, generated in probabilistic sensitivity analysis) between each PIP and an appropriate alternative strategy. Models were then used to evaluate the cost-effectiveness of potential interventions to reduce PIP for each of the three drug classes.

RESULTS

All three PIP drugs and their AEs are associated with greater cost and fewer QALYs compared with alternatives. The largest reduction in QALYs and incremental cost was for benzodiazepines compared with no sedative medication (€3470, 95% CI €2434 to €5001; -0.07 QALYs, 95% CI -0.089 to -0.047), followed by NSAIDs relative to paracetamol (€806, 95% CI €415 and €1346; -0.07 QALYs, 95% CI -0.131 to -0.026), and maximal dose PPIs compared with maintenance dose PPIs (€989, 95% CI -€69 and €2127; -0.01 QALYs, 95% CI -0.029 to 0.003). For interventions to reduce PIP, at a willingness-to-pay of €45 000 per QALY, targeting NSAIDs would be cost-effective up to the highest intervention cost per person of €1971. For benzodiazepine and PPI interventions, the equivalent cost was €1480 and €831, respectively.

CONCLUSIONS

Long-term benzodiazepine and NSAID prescribing are associated with significantly increased costs and reduced QALYs. Targeting inappropriate NSAID prescribing appears to be the most cost-effective PIP intervention.

Prospective utility study of patients with multiple cardiovascular events

OBJECTIVES

The effects of acute coronary syndrome (ACS) events on health-related quality-of-life (HRQoL) and the time dependency of these effects are unknown. This study aimed to characterize health utilities in ACS patients to aid development of future economic models estimating the cost per quality-adjusted life-year impact of ACS events and potential treatments.

METHODS

Multi-center, non-interventional, longitudinal evaluation of health utility in patients experiencing ACS or stroke events. EuroQol-5 dimension 3 level (EQ-5D-3L) surveys were sent to patients (≥18 years) from three UK centers, 1 month after hospital discharge for myocardial infarction (MI), unstable angina (UA), or stroke. Patient demographics, lifestyle, and baseline utility score were collected in the first survey. Follow-up surveys were sent at 6, 12, 18, and 24 months to prospectively capture utility and subsequent health events. Two methods of patient identification were adopted-prospective, where the patient's qualifying events occurred after the study index date, and retrospective, where the patient's qualifying event occurred prior to the study index date. General healthy population utility values were assumed for pre-event HRQoL.

RESULTS

Between January 2011 and March 2014, 2,103 prospectively (n = 1,350)/retrospectively (n = 753) identified patients (mean age = 68.3 years; 67.9% male) responded: MI = 55.9% (n = 1,176), UA = 42.7% (n = 898), stroke = 1.4% (n = 29); 24% had type 2 diabetes. Post-event utility values were lower than general healthy population values, although significant differences in utility between subsequent 6 (n = 1,031, change = -0.002), 12 (n = 1,096, change = -0.008), 18 (n = 1,246, change = -0.007), and 24 (n = 1,277, change = -0.004) month timepoints were not detected. Through multivariate regression analyses, wheelchair use, current smoking, and secondary mental and joint health events were associated with the greatest statistically significant utility decrements.

CONCLUSIONS

This study indicates that health utility decreases following a cardiovascular event and, although some improvement occurs over the subsequent 24 months, general healthy population utility is not necessarily attained.

Differences in utility elicitation methods in cardiovascular disease: a systematic review

AIMS

Utility values inform estimates of the cost-effectiveness of treatment for cardiovascular disease (CVD), but values can vary depending on the method used. The aim of this systematic literature review (SLR) was to explore how methods of elicitation impact utility values for CVD.

MATERIALS AND METHODS

This review identified English-language articles in Embase, MEDLINE, and the gray literature published between September 1992 and August 2015 using keywords for "utilities" and "stroke", "heart failure", "myocardial infarction", or "angina". Variability in utility values based on the method of elicitation, tariff, or type of respondent was then reported.

RESULTS

This review screened 4,341 citations; 290 of these articles qualified for inclusion in the SLR because they reported utility values for one or more of the cardiovascular conditions of interest listed above. Of these 290, the 41 articles that provided head-to-head comparisons of utility methods for CVD were reviewed. In this sub-set, it was found that methodological differences contributed to variation in utility values. Direct methods often yielded higher scores than did indirect methods. Within direct methods, there were no clear trends in head-to-head studies (standard gamble [SG] vs time trade-off); but general population respondents often provided lower scores than did patients with the disease when evaluating the same health states with SG methods. When comparing indirect methods, the EQ-5D typically yielded higher values than the SF-6D, but also showed more sensitivity to differences in health states.

CONCLUSIONS

When selecting CVD utility values for an economic model, consideration of the utility elicitation method is important, as this review demonstrates that methodology of choice impacts utility values in CVD.

Risks associated with antiretroviral treatment for human immunodeficiency virus (HIV): qualitative analysis of social media data and health state utility valuation

Purpose

Despite benefits of antiretroviral therapies (ART), people with HIV infection have increased risk of cardiovascular disease, kidney disease, and low bone mineral density. Some ARTs increase risk of these events. The purpose of this study was to examine patients’ perspectives of these risks and estimate health state utilities associated with these risks for use in cost-utility models.

Methods

Qualitative thematic analysis was conducted to examine messages posted to the POZ/AIDSmeds Internet community forums, focusing on bone, kidney, and cardiovascular side effects and risks of HIV/AIDS medications. Then, health state vignettes were drafted based on this qualitative analysis, literature review, and clinician interviews. The health states (representing HIV, plus treatment-related risks) were valued in time trade-off interviews with general population participants in the UK.

Results

Qualitative analysis of the Internet forums documented patient concerns about ART risks, as well as treatment decisions made because of these risks. A total of 208 participants completed utility interviews (51.4% female; mean age 44.6 years). The mean utility of the HIV health state (virologically suppressed, treated with ART) was 0.86. Adding a description of risk resulted in statistically significant disutility (i.e., utility decreases): renal risk (disutility = −0.02), bone risk (−0.03), and myocardial infarction risk (−0.05).

Conclusions

Patient concerns and treatment decisions were documented via qualitative analysis of Internet forum discussions, and the impact of these concerns was quantified in terms of health state utilities. The resulting disutilities may be useful for differentiating among ARTs in economic modeling of treatment for patients with HIV.

Cost-Effectiveness Analysis of Screening for and Managing Identified Hypertension for Cardiovascular Disease Prevention in Vietnam

OBJECTIVE

To inform development of guidelines for hypertension management in Vietnam, we evaluated the cost-effectiveness of different strategies on screening for hypertension in preventing cardiovascular disease (CVD).

METHODS

A decision tree was combined with a Markov model to measure incremental cost-effectiveness of different approaches to hypertension screening. Values used as input parameters for the model were taken from different sources. Various screening intervals (one-off, annually, biannually) and starting ages to screen (35, 45 or 55 years) and coverage of treatment were analysed. We ran both a ten-year and a lifetime horizon. Input parameters for the models were extracted from local and regional data. Probabilistic sensitivity analysis was used to evaluate parameter uncertainty. A threshold of three times GDP per capita was applied.

RESULTS

Cost per quality adjusted life year (QALY) gained varied in different screening scenarios. In a ten-year horizon, the cost-effectiveness of screening for hypertension ranged from cost saving to Int$ 758,695 per QALY gained. For screening of men starting at 55 years, all screening scenarios gave a high probability of being cost-effective. For screening of females starting at 55 years, the probability of favourable cost-effectiveness was 90% with one-off screening. In a lifetime horizon, cost per QALY gained was lower than the threshold of Int$ 15,883 in all screening scenarios among males. Similar results were found in females when starting screening at 55 years. Starting screening in females at 45 years had a high probability of being cost-effective if screening biannually was combined with increasing coverage of treatment by 20% or even if sole biannual screening was considered.

CONCLUSION

From a health economic perspective, integrating screening for hypertension into routine medical examination and related coverage by health insurance could be recommended. Screening for hypertension has a high probability of being cost-effective in preventing CVD. An adequate screening strategy can best be selected based on age, sex and screening interval.

Health state utilities associated with major clinical events in the context of secondary hyperparathyroidism and chronic kidney disease requiring dialysis

BACKGROUND

Patients with chronic kidney disease (CKD) and secondary hyperparathyroidism (SHPT) who require dialysis are at increased risk for cardiovascular events and bone fractures. To assist in economic evaluations, this study aimed to estimate the disutility of these events beyond the impact of CKD and SHPT.

METHODS

A basic one-year health state was developed describing CKD and SHPT requiring dialysis. Further health states added acute events (cardiovascular events, fractures, and surgical procedures) or chronic post-event effects. Acute health states described a year including an event, and chronic health states described a year subsequent to an event. General population participants in Canada completed time trade-off interviews from which utilities were derived. Pairwise comparisons were made between the basic state and event, and between comparable health states.

RESULTS

A total of 199 participants (54.8% female; mean age = 46.3 years) completed interviews. Each health state had ≥130 valuations. The mean (SD) utility of the basic health state was 0.60 (0.34). For acute events, mean utility differences versus the basic state were: myocardial infarction, -0.06; unstable angina, -0.05; peripheral vascular disease (PVD) with amputation, -0.33; PVD without amputation, -0.11; heart failure, -0.14; stroke, -0.30; hip fracture, -0.14; arm fracture, -0.04; parathyroidectomy, +0.02; kidney transplant, +0.06. Disutilities for chronic health states were: stable angina, -0.09; stroke, -0.27; PVD with amputation, -0.30; PVD without amputation, -0.12; heart failure, -0.14.

CONCLUSIONS

Cardiovascular events and fractures were associated with lower utility scores, suggesting a perceived decrease in quality of life beyond the impact of CKD and SHPT.

Acute and chronic impact of cardiovascular events on health state utilities

BACKGROUND

Cost-utility models are frequently used to compare treatments intended to prevent or delay the onset of cardiovascular events. Most published utilities represent post-event health states without incorporating the disutility of the event or reporting the time between the event and utility assessment. Therefore, this study estimated health state utilities representing cardiovascular conditions while distinguishing between acute impact including the cardiovascular event and the chronic post-event impact.

METHODS

Health states were drafted and refined based on literature review, clinician interviews, and a pilot study. Three cardiovascular conditions were described: stroke, acute coronary syndrome (ACS), and heart failure. One-year acute health states represented the event and its immediate impact, and post-event health states represented chronic impact. UK general population respondents valued the health states in time trade-off tasks with time horizons of one year for acute states and ten years for chronic states.

RESULTS

A total of 200 participants completed interviews (55% female; mean age = 46.6 y). Among acute health states, stroke had the lowest utility (0.33), followed by heart failure (0.60) and ACS (0.67). Utility scores for chronic health states followed the same pattern: stroke (0.52), heart failure (0.57), and ACS (0.82). For stroke and ACS, acute utilities were significantly lower than chronic post-event utilities (difference = 0.20 and 0.15, respectively; both p < 0.0001).

CONCLUSIONS

Results add to previously published utilities for cardiovascular events by distinguishing between chronic post-event health states and acute health states that include the event and its immediate impact. Findings suggest that acute versus chronic impact should be considered when selecting scores for use in cost-utility models. Thus, the current utilities provide a unique option that may be used to represent the acute and chronic impact of cardiovascular conditions in economic models comparing treatments that may delay or prevent the onset of cardiovascular events.

Utility estimates for patients with Type 2 diabetes mellitus after experiencing a myocardial infarction or stroke: a systematic review

A systematic review identified studies eliciting utility decrements from myocardial infarction (MI) and stroke in patients with Type 2 diabetes mellitus (T2DM) and examined their use in economic models of new diabetes treatments. In 16 utility studies in patients with T2DM, utility decrements in the first year ranged from 0.017 to 0.226 for MI and from 0.034 to 0.590 for stroke. Sixteen of 19 economic evaluations of new treatments for T2DM included utility decrements for an MI and/or stroke from one of the 16 utility studies. Decrements for MI ranged from 0.012 to 0.180 in the first year. Decrements for stroke ranged from 0.044 to 0.690 in the first year. Utility studies in patients with T2DM provide little information about changes in utility decrements by time since the event and by disease severity. Cost-effectiveness studies do not always indicate how these values were used in the analysis.