From complexity to clarity: how directed acyclic graphs enhance the study design of systematic reviews and meta-analyses.

While frameworks to systematically assess bias in systematic reviews and meta-analyses (SRMAs) and frameworks on causal inference are well established, they are less frequently integrated beyond the data analysis stages. This paper proposes the use of Directed Acyclic Graphs (DAGs) in the design stage of SRMAs. We hypothesize that DAGs created and registered a priori can offer a useful approach to more effective and efficient evidence synthesis. DAGs provide a visual representation of the complex assumed relationships between variables within and beyond individual studies prior to data analysis, facilitating discussion among researchers, guiding data analysis, and may lead to more targeted inclusion criteria or set of data extraction items. We illustrate this argument through both experimental and observational case examples.

Cost-effectiveness of postoperative imaging surveillance strategies for nonfunctional pituitary adenomas after resection with curative intent.

OBJECTIVE: The aim of this study was to determine an optimal follow-up imaging surveillance strategy in terms of cost-effectiveness after resection of nonfunctioning pituitary adenomas with curative intent. METHODS: An individual-level state-transition microsimulation model was used to simulate costs and outcomes associated with three postoperative imaging strategies over a lifetime time horizon: 1) annual MRI surveillance, 2) tapered MRI surveillance (annual surveillance for 5 years followed by surveillance every 2 years), and 3) personalized surveillance (annual surveillance for 5 years followed by surveillance every 2 years when MRI shows remnant disease/postoperative changes, and surveillance at 7, 10, and 15 years for disease-free MRI). Transition probabilities, utilities, and costs were estimated from recent published data and discounted by 3% annually. Model outcomes included lifetime costs (2022 US dollars), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). RESULTS: Under base case assumptions, annual surveillance yielded higher costs and lower health effects (QALYs) compared with the tapered and personalized surveillance strategies (dominated). Personalized surveillance demonstrated an additional 0.1 QALY at additional cost ($1298) compared with tapered surveillance (7.7 QALYs at a cost of $12,862). The ICER was $11,793/QALY. The optimal decision was most sensitive to the probability of postoperative changes on MRI after surgery and MRI cost. Accounting for parameter uncertainty, personalized surveillance had a higher probability of being a cost-effective surveillance option compared with the alternative strategies at 79%. CONCLUSIONS: Using standard cost-effectiveness thresholds in the US ($100,000/QALY), personalized surveillance that accounted for remnant disease or postoperative changes on MRI was cost-effective compared with alternative surveillance strategies.

Post-operative surveillance for somatotroph, lactotroph and non-functional pituitary adenomas after curative resection: a systematic review.

CONTEXT: Pituitary tumors are the third most common brain tumor and yet there is no standardization of the surveillance schedule and assessment modalities after transsphenoidal surgery. EVIDENCE ACQUISITION: OVID, EMBASE and the Cochrane Library databases were systematically screened from database inception to March 5, 2020. Inclusion and exclusion criteria were designed to capture studies examining detection of pituitary adenoma recurrence in patients 18 years of age and older following surgical resection with curative intent. EVIDENCE SYNTHESIS: A total of 7936 abstracts were screened, with 812 articles reviewed in full text and 77 meeting inclusion criteria for data extraction. A pooled analysis demonstrated recurrence rates at 1 year, 5 years and 10 years for non-functioning pituitary adenomas (NFPA; N = 3533 participants) were 1%, 17%, and 33%, for prolactin-secreting adenomas (PSPA; N = 1295) were 6%, 21%, and 28%, and for growth-hormone pituitary adenomas (GHPA; N = 1257) were 3%, 8% and 13%, respectively. Rates of recurrence prior to 1 year were 0% for NFPA, 1-2% for PSPA and 0% for GHPA. The mean time to disease recurrence for NFPA, PSPA and GHPA were 4.25, 2.52 and 4.18 years, respectively. CONCLUSIONS: This comprehensive review of the literature quantified the recurrence rates for commonly observed pituitary adenomas after transsphenoidal surgical resection with curative intent. Our findings suggest that surveillance within 1 year may be of low yield. Further clinical trials and cohort studies investigating cost-effectiveness of surveillance schedules and impact on quality of life of patients under surveillance will provide further insight to optimize follow-up.

Cost-effectiveness of direct surgery versus preoperative octreotide therapy for growth-hormone secreting pituitary adenomas.

PURPOSE: The objective of this study was to compare the cost-effectiveness of preoperative octreotide therapy followed by surgery versus the standard treatment modality for growth-hormone secreting pituitary adenomas, direct surgery (that is, surgery without preoperative treatment) from a public third-party payer perspective. METHODS: We developed an individual-level state-transition microsimulation model to simulate costs and outcomes associated with preoperative octreotide therapy followed by surgery and direct surgery for patients with growth-hormone secreting pituitary adenomas. Transition probabilities, utilities, and costs were estimated from recent published data and discounted by 3% annually over a lifetime time horizon. Model outcomes included lifetime costs [2020 United States (US) Dollars], quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs). RESULTS: Under base case assumptions, direct surgery was found to be the dominant strategy as it yielded lower costs and greater health effects (QALYs) compared to preoperative octreotide strategy in the second-order Monte Carlo microsimulation. The ICER was most sensitive to probability of remission following primary therapy and duration of preoperative octreotide therapy. Accounting for joint parameter uncertainty, direct surgery had a higher probability of demonstrating a cost-effective profile compared to preoperative octreotide treatment at 77% compared to 23%, respectively. CONCLUSIONS: Using standard benchmarks for cost-effectiveness in the US ($100,000/QALY), preoperative octreotide therapy followed by surgery may not be cost-effective compared to direct surgery for patients with growth-hormone secreting pituitary adenomas but the result is highly sensitive to initial treatment failure and duration of preoperative treatment.

Update of the CHIP (CT in Head Injury Patients) decision rule for patients with minor head injury based on a multicenter consecutive case series.

OBJECTIVE: To update the existing CHIP (CT in Head Injury Patients) decision rule for detection of (intra)cranial findings in adult patients following minor head injury (MHI). METHODS: The study is a prospective multicenter cohort study in the Netherlands. Consecutive MHI patients of 16 years and older were included. Primary outcome was any (intra)cranial traumatic finding on computed tomography (CT). Secondary outcomes were any potential neurosurgical lesion and neurosurgical intervention. The CHIP model was validated and subsequently updated and revised. Diagnostic performance was assessed by calculating the c-statistic. RESULTS: Among 4557 included patients 3742 received a CT (82%). In 383 patients (8.4%) a traumatic finding was present on CT. A potential neurosurgical lesion was found in 73 patients (1.6%) with 26 (0.6%) patients that actually had neurosurgery or died as a result of traumatic brain injury. The original CHIP underestimated the risk of traumatic (intra)cranial findings in low-predicted-risk groups, while in high-predicted-risk groups the risk was overestimated. The c-statistic of the original CHIP model was 0.72 (95% CI 0.69-0.74) and it would have missed two potential neurosurgical lesions and one patient that underwent neurosurgery. The updated model performed similar to the original model regarding traumatic (intra)cranial findings (c-statistic 0.77 95% CI 0.74-0.79, after crossvalidation c-statistic 0.73). The updated CHIP had the same CT rate as the original CHIP (75%) and a similar sensitivity (92 versus 93%) and specificity (both 27%) for any traumatic (intra)cranial finding. However, the updated CHIP would not have missed any (potential) neurosurgical lesions and had a higher sensitivity for (potential) neurosurgical lesions or death as a result of traumatic brain injury (100% versus 96%). CONCLUSIONS: Use of the updated CHIP decision rule is a good alternative to current decision rules for patients with MHI. In contrast to the original CHIP the update identified all patients with (potential) neurosurgical lesions without increasing CT rate.

Surveillance of Unruptured Intracranial Aneurysms: Cost-Effectiveness Analysis for 3 Countries.

BACKGROUND AND OBJECTIVES: No consensus exists on adequate surveillance of conservatively managed unruptured intracranial aneurysms (UIAs). We aimed to determine optimal MRI surveillance strategies for the growth of UIAs using cost-effectiveness analysis. A secondary aim was to develop a clinical tool for personalizing UIA surveillance. METHODS: We designed a microsimulation model from a health care perspective simulating 100,000 55-year-old women to estimate costs and quality-adjusted life years (QALYs) over a lifetime horizon in the United States, the United Kingdom, and the Netherlands, using literature-derived model parameters. Country-specific costs and willingness-to-pay thresholds ($100,000/QALY for the United States, £30,000/QALY for the United Kingdom, and €80,000/QALY for the Netherlands) were used. Lifetime costs and QALYs were annually discounted at 3% for the United States, 3.5% for the United Kingdom, or 4% (costs) and 1.5% (QALYs) for the Netherlands. Strategies were no follow-up surveillance, follow-up with MRI in the first and fifth year after UIA discovery, every 5 years, every 2 years, or annually, or immediate intervention (i.e., clipping or coiling). Using the microsimulation model, we developed a tool for personalizing UIA surveillance for men and women, with different ages and varying aneurysm characteristics. Uncertainty in the input parameters was modeled with probabilistic sensitivity analysis. RESULTS: Among 55-year-old women, 2,222 individuals in the United States, 1,910 in the United Kingdom, and 2,040 in the Netherlands needed to undergo an annual MRI scan to prevent 1 case of subarachnoid hemorrhage per year. No surveillance MRI was most cost-effective in the United States (in 47% of the simulations) and United Kingdom (in 54% of simulations), whereas annual MRI was most cost-effective in the Netherlands (in 53% of simulations). In the United States and United Kingdom, annual surveillance or surveillance in the first and fifth year after discovery was cost-effective in patients <60 years and at increased risk of aneurysm growth. The optimal, personalized, surveillance strategies were summarized in a look-up table for use in clinical practice. DISCUSSION: Generally, the US and UK physicians should refrain from assigning patients, particularly older patients and those with few risk factors for aneurysm growth or rupture, to frequent MRI surveillance. In the Netherlands, annual follow-up is generally most cost-effective.

Long-term Follow-up of a Randomized Clinical Trial Comparing Endovascular Revascularization Plus Supervised Exercise With Supervised Exercise Only for Intermittent Claudication.

OBJECTIVE: The goal of this study was to assess the long-term effectiveness of combination therapy for intermittent claudication, compared with supervised exercise only. BACKGROUND: Supervised exercise therapy is recommended as first-line treatment for intermittent claudication by recent guidelines. Combining endovascular revascularization plus supervised exercise shows promising results; however, there is a lack of long-term follow-up. METHODS: The ERASE study is a multicenter randomized clinical trial, including patients between May 2010 and February 2013 with intermittent claudication. Interventions were combination of endovascular revascularization plus supervised exercise (n = 106) or supervised exercise only (n = 106). Primary endpoint was the difference in maximum walking distance at long-term follow-up. Secondary endpoints included differences in pain-free walking distance, ankle-brachial index, quality of life, progression to critical limb ischemia, and revascularization procedures during follow-up. This randomized trial report is based on a post hoc analysis of extended follow-up beyond that of the initial trial. Patients were followed up until 31 July 2017. Data were analyzed according to the intention-to-treat principle. RESULTS: Median long-term follow-up was 5.4 years (IQR 4.9-5.7). Treadmill test was completed for 128/212 (60%) patients. Whereas the difference in maximum walking distance significantly favored combination therapy at 1-year follow-up, the difference at 5-year follow-up was no longer significant (53 m; 99% CI-225 to 331; P = 0.62). No difference in pain-free walking distance, ankle-brachial index, and quality of life was found during long-term follow-up. We found that supervised exercise was associated with an increased hazard of a revascularization procedure during follow-up (HR 2.50; 99% CI 1.27-4.90; P < 0.001). The total number of revascularization procedures (including randomized treatment) was lower in the exercise only group compared to that in the combination therapy group (65 vs 149). CONCLUSIONS: Long-term follow up after combination therapy versus supervised exercise only, demonstrated no significant difference in walking distance or quality of life between the treatment groups. Combination therapy resulted in a lower number of revascularization procedures during follow-up but a higher total number of revascularizations including the randomized treatment. TRIAL REGISTRATION: Netherlands Trial Registry Identifier: NTR2249.

Cost-effectiveness of a hybrid emergency room system for severe trauma: a health technology assessment from the perspective of the third-party payer in Japan.

BACKGROUND: Hybrid emergency room (ER) systems, consisting of an angiography-computed tomography (CT) machine in a trauma resuscitation room, are reported to be effective for reducing death from exsanguination in trauma patients. We aimed to investigate the cost-effectiveness of a hybrid ER system in severe trauma patients without severe traumatic brain injury (TBI). METHODS: We conducted a cost-utility analysis comparing the hybrid ER system to the conventional ER system from the perspective of the third-party healthcare payer in Japan. A short-term decision tree and a long-term Markov model using a lifetime time horizon were constructed to estimate quality-adjusted life years (QALYs) and associated lifetime healthcare costs. Short-term mortality and healthcare costs were derived from medical records and claims data in a tertiary care hospital with a hybrid ER. Long-term mortality and utilities were extrapolated from the literature. The willingness-to-pay threshold was set at $47,619 per QALY gained and the discount rate was 2%. Deterministic and probabilistic sensitivity analyses were conducted. RESULTS: The hybrid ER system was associated with a gain of 1.03 QALYs and an increment of $33,591 lifetime costs compared to the conventional ER system, resulting in an ICER of $32,522 per QALY gained. The ICER was lower than the willingness-to-pay threshold if the odds ratio of 28-day mortality was < 0.66. Probabilistic sensitivity analysis indicated that the hybrid ER system was cost-effective with a 79.3% probability. CONCLUSION: The present study suggested that the hybrid ER system is a likely cost-effective strategy for treating severe trauma patients without severe TBI.

Quantified health and cost effects of faster endovascular treatment for large vessel ischemic stroke patients in the Netherlands.

BACKGROUND: The effectiveness of endovascular treatment (EVT) for large vessel occlusion (LVO) stroke severely depends on time to treatment. However, it remains unclear what the value of faster treatment is in the years after index stroke. The aim of this study was to quantify the value of faster EVT in terms of health and healthcare costs for the Dutch LVO stroke population. METHODS: A Markov model was used to simulate 5-year follow-up functional outcome, measured with the modified Rankin Scale (mRS), of 69-year-old LVO patients. Post-treatment mRS was extracted from the MR CLEAN Registry (n=2892): costs per unit of time and Quality-Adjusted Life Years (QALYs) per mRS sub-score were retrieved from follow-up data of the MR CLEAN trial (n=500). Net Monetary Benefit (NMB) at a willingness to pay of €80 000 per QALY was reported as primary outcome, and secondary outcome measures were days of disability-free life gained and costs. RESULTS: EVT administered 1 min faster resulted in a median NMB of €309 (IQR: 226;389), 1.3 days of additional disability-free life (IQR: 1.0;1.6), while cumulative costs remained largely unchanged (median: -€15, IQR: -65;33) over a 5-year follow-up period. As costs over the follow-up period remained stable while QALYs decreased with longer time to treatment, which this results in a near-linear decrease of NMB. Since patients with faster EVT lived longer, they incurred more healthcare costs. CONCLUSION: One-minute faster EVT increases QALYs while cumulative costs remain largely unaffected. Therefore, faster EVT provides better value of care at no extra healthcare costs.

Evidence-Based Medicine in Otolaryngology, Part XI: Modeling and Analysis to Support Decisions.

OBJECTIVE: To provide a resource to educate clinical decision makers about the analyses and models that can be employed to support data-driven choices. DATA SOURCES: Published studies and literature regarding decision analysis, decision trees, and models used to support clinical decisions. REVIEW METHODS: Decision models provide insights into the evidence and its implications for those who make choices about clinical care and resource allocation. Decision models are designed to further our understanding and allow exploration of the common problems that we face, with parameters derived from the best available evidence. Analysis of these models demonstrates critical insights and uncertainties surrounding key problems via a readily interpretable yet quantitative format. This 11th installment of the Evidence-Based Medicine in Otolaryngology series thus provides a step-by-step introduction to decision models, their typical framework, and favored approaches to inform data-driven practice for patient-level decisions, as well as comparative assessments of proposed health interventions for larger populations. CONCLUSIONS: Information to support decisions may arise from tools such as decision trees, Markov models, microsimulation models, and dynamic transmission models. These data can help guide choices about competing or alternative approaches to health care. IMPLICATIONS FOR PRACTICE: Methods have been developed to support decisions based on data. Understanding the related techniques may help promote an evidence-based approach to clinical management and policy.

Do Case-Control Studies Always Estimate Odds Ratios?

Case-control studies are an important part of the epidemiologic literature, yet confusion remains about how to interpret estimates from different case-control study designs. We demonstrate that not all case-control study designs estimate odds ratios. On the contrary, case-control studies in the literature often report odds ratios as their main parameter even when using designs that do not estimate odds ratios. Only studies using specific case-control designs should report odds ratios, whereas the case-cohort and incidence-density sampled case-control studies must report risk ratio and incidence rate ratios, respectively. This also applies to case-control studies conducted in open cohorts, which often estimate incidence rate ratios. We also demonstrate the misinterpretation of case-control study estimates in a small sample of highly cited case-control studies in general epidemiologic and medical journals. We therefore suggest that greater care be taken when considering which parameter is to be reported from a case-control study.

Public health and cost consequences of time delays to thrombectomy for acute ischemic stroke.

OBJECTIVE: To determine public health and cost consequences of time delays to endovascular thrombectomy (EVT) for patients, health care systems, and society, we estimated quality-adjusted life-years (QALYs) of EVT-treated patients and associated costs based on times to treatment. METHODS: The Markov model analysis was performed from US health care and societal perspectives over a lifetime horizon. Contemporary data from 7 trials within the Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials (HERMES) collaboration served as data source. Aside from cumulative lifetime costs, we calculated the net monetary benefit (NMB) to determine the economic value of care. We used a contemporary willingness-to-pay threshold of $100,000 per QALY for NMB calculations. RESULTS: Every 10 minutes of earlier treatment resulted in an average gain of 39 days (95% prediction interval 23-53 days) of disability-free life. Overall, the cumulative lifetime costs for patients with earlier or later treatment were similar. Patients with later treatment had higher morbidity-related costs but over a shorter time span due to their shorter life expectancy, resulting in similar lifetime costs as in patients with early treatment. Regarding the economic value of care, every 10 minutes of earlier treatment increased the NMB by $10,593 (95% prediction interval $5,549-$14,847) and by $10,915 (95% prediction interval $5,928-$15,356) taking health care and societal perspectives, respectively. CONCLUSIONS: Any time delay to EVT reduces QALYs and decreases the economic value of care provided by this intervention. Health care policies to implement efficient prehospital triage and to accelerate in-hospital workflow are urgently needed.

Public Health and Cost Benefits of Successful Reperfusion After Thrombectomy for Stroke.

Background and Purpose- The benefit that endovascular thrombectomy offers to patients with stroke with large vessel occlusions depends strongly on reperfusion grade as defined by the expanded Thrombolysis in Cerebral Infarction (eTICI) scale. Our aim was to determine the lifetime health and cost consequences of the quality of reperfusion for patients, healthcare systems, and society. Methods- A Markov model estimated lifetime quality-adjusted life years (QALY) and lifetime costs of endovascular thrombectomy-treated patients with stroke based on eTICI grades. The analysis was performed over a lifetime horizon in a United States setting, adopting healthcare and societal perspectives. The reference case analysis was conducted for stroke at 65 years of age. National health and cost consequences of improved eTICI 2c/3 reperfusion rates were estimated. Input parameters were based on best available evidence. Results- Lifetime QALYs increased for every grade of improved reperfusion (median QALYs for eTICI 0/1: 2.62; eTICI 2a: 3.46; eTICI 2b: 5.42; eTICI 2c: 5.99; eTICI 3: 6.73). Achieving eTICI 3 over eTICI 2b reperfusion resulted on average in 1.31 incremental QALYs as well as healthcare and societal cost savings of $10 327 and $20 224 per patient. A 10% increase in the eTICI 2c/3 reperfusion rate of all annually endovascular thrombectomy-treated patients with stroke in the United States is estimated to yield additional 3656 QALYs and save $21.0 million and $36.8 million for the healthcare system and society, respectively. Conclusions- Improved reperfusion grants patients with stroke additional QALYs and leads to long-term cost savings. Procedural strategies to achieve complete reperfusion should be assessed for safety and feasibility, even when initial reperfusion seems to be adequate.

Personalized E-Coaching in Cardiovascular Risk Reduction: A Randomized Controlled Trial.

OBJECTIVES: To assess whether electronic (e-) coaching, using personalized web-based lifestyle and risk factor counselling with additional email prompts, provides additional risk reduction when added to standard of care (SOC) in individuals at increased risk. METHODS: Between June 2013 and May 2015, 402 participants were allocated 1:1 to e-coaching and SOC versus SOC. Participants free of manifest cardiovascular disease, with internet access, and a 10-year QRISK2 cardiovascular risk of ≥10% were enrolled. Change in oscillometric carotid-femoral pulse wave velocity (PWV) from baseline to six months was the primary endpoint. Secondary outcomes included change in blood pressure (BP), weight, and risk scores. Analysis was by intention to treat. RESULTS: Mean (±SD) age was 65.5 (5.6) years with 37% females. Primary outcome data were available for 94%. There was no difference in PWV reductions between e-coaching and standard of care groups (-0.16 m/s vs. -0.25 m/s, 95% confidence interval -0.39 to 0.22, p = 0.56). There were no differences in the improvement between groups for BP, weight, Framingham, or QRISK2 scores. Pulse wave velocity change was more favorable in those with a higher level of education (p = 0.04), but was not associated with age, gender, presence of diabetes, baseline QRISK2 score, or logins to the website. CONCLUSIONS: In individuals at increased cardiovascular risk, a comprehensive 'health check' program modestly reduced future risk. Personalized e-coaching did not provide added risk reduction. Currently there is no evidence to routinely recommend e-coaching in cardiovascular health check programs. TRIAL REGISTRATION: HAPPY London ClinicalTrials.gov: NCT01911910.

Evidence-Based Medicine in Otolaryngology Part 10: Cost-Effectiveness Analyses in Otolaryngology.

Clinicians seek to pursue the most clinically effective treatment strategies, but costs have also become a key determinant in contemporary health care. Economic analyses have thus emerged as a valuable resource to both quantify and qualify the value of existing and emerging interventions and programs. Cost-effectiveness analyses estimate the benefits gained per monetary unit, providing insights to guide resource allocation. Herein, we delineate the related concepts and considerations to facilitate understanding and appraisal of these analyses, so as to better inform the stakeholders in our otolaryngology community.

Risk of Intracranial Complications in Minor Head Injury: The Role of Loss of Consciousness and Post-Traumatic Amnesia in a Multi-Center Observational Study.

Various guidelines for minor head injury focus on patients with a Glasgow Coma Scale (GCS) score of 13-15 and loss of consciousness (LOC) or post-traumatic amnesia (PTA), while clinical management for patients without LOC or PTA is often unclear. We aimed to investigate the effect of presence and absence of LOC or PTA on intracranial complications in minor head injury. A prospective multi-center cohort study of all patients with blunt head injury and GCS score of 15 was conducted at six Dutch centers between 2015 and 2017. Five centers used the national guideline and one center used a local guideline-both based on the CT in Head Injury Patients (CHIP) prediction model-to identify patients in need of a computed tomography (CT) scan. We studied the presence of traumatic findings and neurosurgical interventions in patients with and without LOC or PTA. In addition, we assessed the association of LOC and PTA with traumatic findings with logistic regression analysis and the additional predictive value of LOC and PTA compared with other risk factors in the CHIP model. Of 3914 patients, 2249 (58%) experienced neither LOC nor PTA and in 305 (8%) LOC and PTA was unknown. Traumatic findings were present in 153 of 1360 patients (11%) with LOC or PTA and in 67 of 2249 patients (3%) without LOC and PTA. Five patients without LOC and PTA had potential neurosurgical lesions and one patient underwent a neurosurgical intervention. LOC and PTA were strongly associated with traumatic findings on CT, with adjusted odds ratios of 2.9 (95% confidence interval [CI] 2.2-3.8) and 3.5 (95% CI 2.7-4.6), respectively. To conclude, patients who had minor head injury with neither LOC nor PTA are at risk of intracranial complications. Clinical guidelines should include clinical management for patients without LOC and PTA, and they should include LOC and PTA as separate risk factors rather than as diagnostic selection criteria.

Management of Reducible Ventral Hernias: Clinical Outcomes and Cost-effectiveness of Repair at Diagnosis Versus Watchful Waiting.

OBJECTIVE: To compare long-term clinical and economic outcomes associated with 3 management strategies for reducible ventral hernia: repair at diagnosis (open or laparoscopic) and watchful waiting. BACKGROUND: There is variability in ventral hernia management. Recent data suggest watchful waiting is safe; however, long-term clinical and economic outcomes for different management strategies remain unknown. METHODS: We built a state-transition microsimulation model to forecast outcomes for individuals with reducible ventral hernia, simulating a cohort of 1 million individuals for each strategy. We derived cohort characteristics (mean age 58 years, 63% female), hospital costs, and perioperative mortality from the Nationwide Inpatient Sample (2003-2011), and additional probabilities, costs, and utilities from the literature. Outcomes included prevalence of any repair, emergent repair, and recurrence; lifetime costs; quality-adjusted life years (QALYs); and incremental cost-effectiveness ratios. We performed stochastic and probabilistic sensitivity analyses to identify parameter thresholds that affect optimal management, using a willingness-to-pay threshold of $50,000/QALY. RESULTS: With watchful waiting, 39% ultimately required repair (14% emergent) and 24% recurred. Seventy per cent recurred with repair at diagnosis. Laparoscopic repair at diagnosis was cost-effective compared with open repair at diagnosis (incremental cost-effectiveness ratio $27,700/QALY). The choice of operative strategy (open vs laparoscopic) was sensitive to cost and postoperative quality of life. When perioperative mortality exceeded 5.2% or yearly recurrence exceeded 19.2%, watchful waiting became preferred. CONCLUSIONS: Ventral hernia repair at diagnosis is very cost-effective. The choice between open and laparoscopic repair depends on surgical costs and postoperative quality of life. In patients with high risk of perioperative mortality or recurrence, watchful waiting is preferred.

Evaluation of T2-W MR imaging and diffusion-weighted imaging for the early post-treatment local response assessment of patients treated conservatively for cervical cancer: a multicentre study.

OBJECTIVES: To compare MR imaging with or without DWI and clinical response evaluation (CRE) in the local control evaluation of cervical carcinoma after radiotherapy. METHODS: In a multicentre university setting, we prospectively included 107 patients with primary cervical cancer treated with radiotherapy. Sensitivity and specificity for CRE and MR imaging (with pre-therapy MR imaging as reference) (2 readers) were evaluated using cautious and strict criteria for identifying residual tumour. Nested logistic regression models were constructed for CRE, subsequently adding MR imaging with and without DWI as independent variables, as well as the pre- to post-treatment change in apparent diffusion coefficient (delta ADC). RESULTS: Using cautious criteria, CRE and MR imaging with DWI (reader 1/reader 2) have comparable high specificity (83% and 89%/95%, respectively), whereas MR imaging without DWI showed significantly lower specificity (63%/53%) than CRE. Using strict criteria, CRE and MR imaging with DWI both showed very high specificity (99% and 92%/95%, respectively), whereas MR imaging without DWI showed significantly lower specificity (89%/77%) than CRE. All sensitivities were not significantly different. Addition of MR imaging with DWI to CRE has statistically significant incremental value in identifying residual tumour (reader 1: estimate, 1.06; p = 0.001) (reader 2: estimate, 0.62; p = 0.02). Adding the delta ADC did not have significant incremental value in detecting residual tumour. CONCLUSIONS: DWI significantly increases the specificity of MR imaging in the detection of local residual tumour. Furthermore, MR imaging with DWI has significant incremental diagnostic value over CRE, whereas adding the delta ADC has no incremental diagnostic value. KEY POINTS: • If MR imaging is used for response evaluation, DWI should be incorporated • MR imaging with DWI has diagnostic value comparable/complementary to clinical response evaluation • Inter-reader agreement is moderate to fair for two experienced radiologist readers • Quantitative measurements of ADC early post-therapy have limited diagnostic value.

Evidence-Based Medicine in Otolaryngology Part 9: Valuing Health Outcomes.

Decisions about resource allocation are increasingly based on value trade-offs between health outcomes and cost. This process relies on comprehensive and standardized definitions of health status that accurately measure the physical, mental, and social well-being of patients across disease states. These metrics, assessed through clinical trials, observational studies, and health surveys, can facilitate the integration of patient preferences into clinical practice. This ninth installment in the Evidence-Based Medicine in Otolaryngology Series is a practical overview of health outcome valuation, as well as the integration of both quality and quantity of life into standardized metrics for health research, program planning, and resource allocation. Tools for measuring preference-based health states, measures of effectiveness, and the application of metrics in economic evaluations are discussed.