Cost-of-Illness Studies in the United States: A Systematic Review of Methodologies Used for Direct Cost

Department of Health Management and Policy, University of Iowa, Iowa City, IA, USA.
Value in Health (Impact Factor: 3.28). 02/2008; 11(1):13-21. DOI: 10.1111/j.1524-4733.2007.00210.x
Source: PubMed


We undertake a systematic review to examine the methods used by researchers in developing cost-of-illness (COI) studies. This review aims to categorize the approaches that the published literature uses in terms of perspective, scope, components of care analyzed in the literature, data sets, and valuation approaches used for direct cost. It draws conclusions regarding the adequacy of current COI research methods and makes recommendations on improving them.
The online bibliographic information service HealthSTAR (which incorporates MEDLINE) was used to search for COI studies in the research literature published during the period from 2000 to 2004. The search strategy used the term "cost of illness" as a MeSH (medical subject heading) term.
The HealthSTAR literature search identified references to 650 articles. Review of abstracts resulted in the identification of 170 of these for a more detailed review. This process identified 52 articles that met all criteria of COI studies. We identified 218 components of care analyzed across the 52 articles. Private-insurance or employer-claims data sets comprised the largest source of utilization and cost information among the studies.
Analyzing cost of illness presents useful opportunities for communicating with the public and policymakers on the relative importance of specific diseases and injuries. Our research, however, indicates that COI studies employ varied approaches and many articles have methodological limitations. Without well-accepted standards to guide researchers in their execution of these studies, policymakers and the general public must be wary of the methods used in their calculation and subsequent results.


Available from: Marcia M Ward
  • Source
    • "Operational expenditures for healthcare facilities and personal transportation costs are examples of indirect costs [14]. Costs incurred at the population level are deemed societal costs [8,9,12], which are costs that cannot be completely attributed to an individual’s illness but can be incurred when a person or a group of people become ill [15]. Societal costs primarily include expenditures incurred by industry and government [16]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Governments require high-quality scientific evidence to prioritize resource allocation and the cost-of-illness (COI) methodology is one technique used to estimate the economic burden of a disease. However, variable cost inventories make it difficult to interpret and compare costs across multiple studies. Methods A scoping review was conducted to identify the component costs and the respective data sources used for estimating the cost of foodborne illnesses in a population. This review was accomplished by: (1) identifying the research question and relevant literature, (2) selecting the literature, (3) charting, collating, and summarizing the results. All pertinent data were extracted at the level of detail reported in a study, and the component cost and source data were subsequently grouped into themes. Results Eighty-four studies were identified that described the cost of foodborne illness in humans. Most studies (80%) were published in the last two decades (1992–2012) in North America and Europe. The 10 most frequently estimated costs were due to illnesses caused by bacterial foodborne pathogens, with non-typhoidal Salmonella spp. being the most commonly studied. Forty studies described both individual (direct and indirect) and societal level costs. The direct individual level component costs most often included were hospital services, physician personnel, and drug costs. The most commonly reported indirect individual level component cost was productivity losses due to sick leave from work. Prior estimates published in the literature were the most commonly used source of component cost data. Data sources were not provided or specifically linked to component costs in several studies. Conclusions The results illustrated a highly variable depth and breadth of individual and societal level component costs, and a wide range of data sources being used. This scoping review can be used as evidence that there is a lack of standardization in cost inventories in the cost of foodborne illness literature, and to promote greater transparency and detail of data source reporting. By conforming to a more standardized cost inventory, and by reporting data sources in more detail, there will be an increase in cost of foodborne illness research that can be interpreted and compared in a meaningful way.
    BMC Public Health 05/2014; 14(1):509. DOI:10.1186/1471-2458-14-509 · 2.26 Impact Factor
  • Source
    • "factors, among which the most important are differences in the organisation of health service provision, in the used methodologies of COI studies (Clabaugh and Ward 2008), and the different and changing costs over time. For Germany, the reported COI of HF varies between 2,100 und 9,100 euros, and hospital care accounts for 45-72 % of costs (Zugck et al. 2010; Neumann et al. 2009). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Aims Heart failure (HF) represents an increasing burden on health-care systems because of the aging population. The aim of this study was to explore its costs of care in Germany from the payer perspective and to identify the main drivers. Subjects and methods As part of a trial, primary care physicians (PCPs) enrolled eligible patients and documented actual clinical and 12-month retrospective ambulatory health-care utilisation data related to HF [PCP and cardiologist contacts, and cardiovascular (CV) medication] and provided the doctors’ reports of hospitalisations during 2004 and 2005, enabling the collection and calculation of costs. Furthermore, each hospitalisation was classified according to the cause of admission into HF, CV or other hospitalisation. Results Thirty-seven physicians enrolled 168 patients with complete data of 159 patients (95 %). Patients (mean age 68 ± 10 years, 73 % male, 47 % ischaemic aetiology) had ascertained systolic HF (mean ejection fraction 33 ± 7 %) with NYHA class II/III in 53/45 %. Mean (SD; median) annual costs of 96 hospitalisations, CV medication, and 337 cardiologist and 3,037 PCP practice contacts were 3,545 (8,065; 0), 854 (835; 638), 117 (105; 106) and 269 (190; 233) euros, respectively, totalling 4,792 (8249;1341) euros. Fourteen per cent of all patients incurred 50 % of total costs. Twenty-five HF, 49 CV and 22 other hospitalisations incurred 13, 73 and 14 % of hospital care costs, respectively. Conclusions These secondary outcome data might indicate a trend that neither HF ambulatory care nor hospitalisation but rather interventional cardiology is the main cost driver. Planning interventions aimed at reduced hospitalisation and costs should include further clarification of the mechanisms of CV hospitalisation and reimbursement.
    Journal of Public Health 12/2012; 20:1-8. DOI:10.1007/s10389-012-0501-3 · 2.06 Impact Factor
  • Source
    • "Study quality also varied considerably. Although methods were not the focus of our work (as, e.g., in Clabaugh and Ward [44]), we found that studies included in this review varied in the number , type, and categorization of cost components, and often lacked specificity in the exact methods used for identifying AF-specific costs. No study provided a complete societal perspective including all productivity, nonmedical, and patient-borne costs. "
    [Show abstract] [Hide abstract]
    ABSTRACT: To systematically review and synthesize the literature on the costs of atrial fibrillation (AF) with attention to study design and costing methods, geography, and intervention approaches. A systematic search for previously published studies reporting the costs for AF patients was conducted. Data were analyzed in three steps: first by evaluating overall system costs; second by evaluating the relative contribution of specific cost components; and third by examining variations across study designs, across primary treatment approach, and by geography. Finally, a specific review of the treatment costs associated with anticoagulation treatment was examined given the clinical importance and attention given to these costs in the literature. The literature search resulted in 115 articles. On review of the abstracts or full text of these articles, 21 articles met all study criteria and reported on health system AF-related direct costs. A further six articles focused exclusively on anticoagulation costs for patients with AF. The overall average annual system cost across 27 estimates obtained from the literature was $5450 (SD = $3624) in 2010 Canadian dollars and ranged from a low of $1,632 to a high of $21,099. About one-third of these costs could be attributed to anticoagulation management. The largest cost component was acute care, followed by outpatient and physician and then medication-related costs. AF-related medical costs are high, reflecting resource-intensive and long-term treatments including anticoagulation treatment. These costs, accompanied with increasing prevalence, justify increased attention to the management of patients with AF. Future studies of AF cost should ensure a broad assessment of the incremental direct medical and societal cost associated with this diagnosis.
    Value in Health 03/2012; 15(2):240-8. DOI:10.1016/j.jval.2011.09.009 · 3.28 Impact Factor
Show more