This is an excellent and important area for a systematic review! Telemedicine interventions are diverse, and understanding their cost-effectiveness is crucial for resource allocation.

Let's break down how to systematically approach this, covering not just the search but also other critical aspects of your review.

Systematic Review of Cost-Effectiveness Studies of Telemedicine Interventions

Part 1: Searching Economic and Medical Databases

To ensure a comprehensive search, you'll need to go beyond just economic databases, as many cost-effectiveness analyses (CEAs) are published in general medical or specialty journals and indexed in broader biomedical databases.

A. Key Databases to Search:

• Dedicated Health Economic Databases:


• NHS Economic Evaluation Database (NHS EED): (As you mentioned) Excellent for directly identifying full economic evaluations. Maintained by CRD, University of York.


• Health Technology Assessment (HTA) Database (part of The Cochrane Library): Also from CRD, contains details of HTA reports, which often include economic evaluations.


• EconLit: While broader economics, it can capture health economics papers not always indexed elsewhere.


• Major Biomedical Databases:


• PubMed/MEDLINE: Essential for biomedical literature. Use MeSH terms for precise searching.


• Embase: Strong for pharmacology, medical devices, and clinical medicine. Emtree terms are crucial here.


• Web of Science (Core Collection): Excellent for multidisciplinary coverage, citation tracking, and identifying highly cited papers. Includes Science Citation Index Expanded, Social Sciences Citation Index, etc.


• Scopus: Similar to Web of Science, broad multidisciplinary coverage, good for citation analysis.


• Specialized & Grey Literature Sources:


• Cochrane Central Register of Controlled Trials (CENTRAL): While focused on trials, many trials include economic endpoints or sub-studies.


• PsycINFO: If your telemedicine scope includes mental health interventions.


• Google Scholar: Useful for identifying grey literature, conference proceedings, or articles missed by traditional databases. Be prepared for a higher volume of irrelevant results.


• Specific HTA Agency Websites: (e.g., NICE, CADTH, AHRQ, IQWiG, PBAC) Check their published reports and guidelines, as these often contain or refer to economic evaluations.


• Professional Society Websites/Journals: (e.g., ISPOR, AHSR, HEOR journals).

You'll need to combine terms related to telemedicine interventions with terms related to economic evaluation.

Core Components:

• Intervention Terms (Telemedicine/Telehealth):


• telemedicine OR telehealth OR eHealth OR mHealth OR virtual care OR remote monitoring OR teleconsultation OR telepresence OR teleradiology OR telepathology OR teleICU OR telenursing OR tele-rehabilitation OR "digital health"


• Use truncation (tele*) where appropriate to capture variations (telemedicine, telemedecine, etc.).


• Consider specific types if your review is narrower (e.g., (telemedicine OR telehealth) AND (diabetes OR "chronic disease management")).


• Economic Evaluation Terms:


• cost-effectiveness OR "cost effectiveness" OR cost-utility OR "cost utility" OR cost-benefit OR "cost benefit" OR "economic evaluation" OR "economic analysis" OR "health economic" OR "economic modelling" OR "value for money" OR "cost minimisation" OR "cost minimization" OR "cost-of-illness" OR cost (using cost to catch cost-saving, cost-reducing, etc., but be mindful of broadness).


• Specific MeSH/Emtree terms: ("Cost-Effectiveness Analysis"[MeSH]) OR ("Economic Evaluation"[MeSH]) OR ("Health Care Costs"[MeSH]).

This is a template; you'll need to adapt it for each database, leveraging their specific syntax (e.g., MeSH terms in PubMed, Emtree in Embase, different field codes).

((telemedicine[MeSH] OR telehealth[tiab] OR eHealth[tiab] OR mHealth[tiab] OR "virtual care"[tiab] OR "remote monitoring"[tiab] OR teleconsultation[tiab] OR telepresence[tiab] OR teleradiology[tiab] OR telepathology[tiab] OR teleICU[tiab] OR telenursing[tiab] OR "tele-rehabilitation"[tiab] OR "digital health"[tiab])
AND
("Cost-Effectiveness Analysis"[MeSH] OR "Economic Evaluation"[MeSH] OR "Health Care Costs"[MeSH] OR cost-effectiveness[tiab] OR "cost effectiveness"[tiab] OR cost-utility[tiab] OR "cost utility"[tiab] OR cost-benefit[tiab] OR "cost benefit"[tiab] OR "economic evaluation"[tiab] OR "economic analysis"[tiab] OR "health economic"[tiab] OR "value for money"[tiab] OR "cost minimisation"[tiab] OR "cost minimization"[tiab] OR "cost-of-illness"[tiab] OR cost*[tiab]))

D. Search Strategy Best Practices:

• Pilot Searches: Run initial searches to identify relevant terms, MeSH/Emtree headings, and scope.


• Documentation: Keep a detailed record of all databases searched, search strings used, dates of search, and number of results. This is crucial for transparency and reproducibility (PRISMA guidelines).


• Limits/Filters:


• Language: English (or other relevant languages).


• Publication Dates: Define your timeframe (e.g., "published after 2000").


• Study Type: Some databases allow filtering for "economic evaluation" or specific study designs, but use with caution as it can sometimes be too restrictive.


• Human Studies: Exclude animal studies.


• Duplicate Management: Use reference management software (EndNote, Zotero, Mendeley) to import all results and remove duplicates.

Part 2: Beyond the Search – The Full Systematic Review Process

Once you've completed your comprehensive search, the systematic review really begins.

1. Eligibility Criteria:

Clearly define what makes a study suitable for inclusion. This should be established before screening.

• Study Design: Only full economic evaluations (Cost-Effectiveness Analysis (CEA), Cost-Utility Analysis (CUA), Cost-Benefit Analysis (CBA), Cost-Minimization Analysis (CMA)). Exclude budget impact analyses, simple cost analyses, or burden of illness studies unless they include comparative effectiveness.


• Intervention: Telemedicine/telehealth intervention, clearly defined.


• Comparator: Should compare telemedicine to usual care, another telemedicine modality, or no intervention.


• Outcomes: Must report economic outcomes (e.g., costs, QALYs, LYs, ICERs).


• Population: Specify if there's a target population (e.g., patients with chronic conditions, elderly, specific disease groups).


• Setting: (e.g., primary care, hospital, home-based).


• Language & Publication Date: Consistent with your search.

• Two-Stage Process:


• Title and Abstract Screening: Two independent reviewers will screen all titles and abstracts against the eligibility criteria. Discrepancies are resolved by discussion or a third reviewer.


• Full-Text Review: Retrieve full texts of all potentially relevant articles. Two independent reviewers will read these against the eligibility criteria. Record reasons for exclusion for each full-text article (crucial for your PRISMA flow diagram).


• PRISMA Flow Diagram: Document the number of records identified, screened, excluded (with reasons), and included at each stage.

Develop a standardized data extraction form before starting. This should be piloted on a few articles and revised as needed. Two independent reviewers should extract data to ensure accuracy.

Key data points to extract:

• Study Characteristics: Authors, year, country, funding, study setting, type of telemedicine intervention.


• Intervention & Comparator Details: Specifics of the telemedicine intervention (technology, duration, frequency, target population, providers) and the comparator.


• Methodology:


• Type of economic evaluation (CEA, CUA, CBA, CMA).


• Perspective (e.g., societal, healthcare payer, patient).


• Time horizon.


• Discount rate (for costs and effects).


• Source of effectiveness data (e.g., RCT, observational study, modeling).


• Main outcome measure (e.g., QALYs, DALYs, life-years gained).


• Cost components included (e.g., intervention costs, healthcare resource use, patient costs).


• Handling of uncertainty (e.g., sensitivity analyses, probabilistic sensitivity analysis).


• Results:


• Total costs (intervention & comparator).


• Total effects (intervention & comparator).


• Incremental Cost-Effectiveness Ratio (ICER), Incremental Cost-Utility Ratio (ICUR), or Net Monetary Benefit (NMB).


• Conclusion regarding cost-effectiveness.


• Results of sensitivity analyses.

This is critical for economic evaluations. You need to assess the methodological rigor and reporting quality of the included studies.

• Recommended Tools:


• CHEERS Checklist (Consolidated Health Economic Evaluation Reporting Standards): While primarily for reporting, it's a good guide for what should be in a high-quality economic evaluation and can serve as a proxy for methodological quality if items are clearly reported.


• Drummond Checklist (or variations): A widely used checklist specifically designed for assessing the methodological quality of economic evaluations.


• Quality of Health Economic Studies (QHES) instrument: Another option for assessing quality.


• NICE/ISPOR Guidelines: Familiarize yourself with these guidelines, as they represent best practices in conducting economic evaluations.


• Key Domains to Assess:


• Perspective: Is it appropriate and clearly stated?


• Time Horizon: Is it long enough to capture all relevant costs and effects?


• Discounting: Are costs and effects discounted appropriately for studies longer than one year?


• Costs: Are all relevant cost components identified, measured, and valued appropriately?


• Outcomes: Are health outcomes measured appropriately (e.g., QALYs derived from valid utility measures)?


• Incremental Analysis: Is a proper incremental analysis performed?


• Uncertainty: Are sensitivity analyses performed and adequately reported to address uncertainty in key parameters?


• Transparency: Are methods and data sources clearly reported?

Economic evaluations are often heterogeneous (different methods, perspectives, populations, interventions), making quantitative meta-analysis of ICERs challenging.

• Descriptive Synthesis:


• Summarize the characteristics of included studies (tables of study design, intervention, comparator, population, country, year).


• Describe the type of telemedicine interventions studied and the health conditions.


• Summarize the reported ICERs, cost-effectiveness conclusions, and main drivers of cost-effectiveness across studies.


• Qualitative Synthesis:


• Identify common themes and trends regarding cost-effectiveness.


• Explore reasons for heterogeneity (e.g., differences in perspective, time horizon, specific telemedicine modality, patient population, healthcare system).


• Discuss the robustness of findings, particularly with respect to sensitivity analyses.


• Compare findings to established cost-effectiveness thresholds (e.g., country-specific willingness-to-pay thresholds).


• Visualizations:


• Forest plots for cost differences or effect differences (if comparable).


• Cost-effectiveness planes (if sufficient data allows for plotting).


• Summary tables of ICERs and conclusions, potentially stratified by type of telemedicine or disease.

• Follow the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement for reporting your review.


• Additionally, ensure your reporting aligns with best practices for systematic reviews of economic evaluations, often drawing on elements from the CHEERS checklist for describing the included studies.


• Clearly articulate your methods, results, limitations, and conclusions. Discuss the implications for policy and future research.

This systematic approach will ensure your review is rigorous, comprehensive, and provides valuable insights into the cost-effectiveness of telemedicine interventions. Good luck!