Incremental costs associated with myocardial infarction and stroke in patients with type 2 diabetes mellitus: an overview for economic modeling

Figures & data

Figure 1. PRISMA diagram. PRISMA = Preferred Reporting Items for Systematic Reviews and Meta-Analyses; NHS EED = National Health Service Economic Evaluation Database.

Table 1. Summary of characteristics of key cost studies.

Cost year	Study	Study type	Methodology	Population	Sample size	Response rate	Outcomes reported	Appropriateness for economic analysis^a
Canada
2002	O’Reilly et al.7	Economic model with cost analysis.	Resource use identified from Ontario Diabetes database, hospital discharge database, and same day surgery database, Ontario health insurance database, Ontario Drug benefit database, and Ontario Home Care Administration system database. Unit costs were applied.	Resource use estimates for the cost of MI and stroke were derived from the resource utilization profiles for a cohort of 734,113 patients with T2DM, which were collected over a 10-year timeframe.	734,113	N/A	Cost of MI and stroke in year of event and each subsequent year.	13/15. Productivity changes not included. Generalizability of results to other settings and patient/client groups not clearly discussed.
2000	O’Brien et al.41	Cost analysis.	Resource use data were collected from several sources: ▪ Database review ▪ Survey data ▪ Previously published economic model (for stroke costs).	N/A	N/A	N/A	MI and stroke. Event costs: those associated with resource use specific to the defining clinical event; Include both acute care and event-related healthcare delivered in the first year. State costs: annual management costs for years subsequent to the event year.	9/15. Does not provide detail on how resource use profiles determined. Does not report unit costs and resource use.
1996	O’Brien et al.42	Cost analysis	Resource use data collected from several Canadian sources including Ontario Case Cost Project, physician and laboratory fee schedules, government reports and literature.	N/A	N/A	N/A	MI and stroke: event costs and state costs.	9/15 No details on how ‘typical’ resource use profiles were provided. Unit costs were not reported alongside resource use estimates.
Croatia
2009	Saric et al.43	Economic model.	Health resource use and medical costs determined using surveys and reports issued by Croatian National Diabetes Registry.	Patients with T2DM.	N/A	N/A	National cost of MI and stroke complications in patients with T2DM.	8/15. Time horizon not reported. No details on determination of resource use profiles. Resource use quantities and unit costs not reported. Generalizability of results to other settings not discussed.
Czech Republic
2008	Weber et al.27	Matched-pair analysis (SMBG users vs non-users) based on cohorts of a large retrospective study of patients with T2DM.	Review of physician records from patients included in the ROSSO study.	Patients with T2DM.	Sample size for estimation of complication costs not reported.	N/A	Year 1 cost of MI and stroke Cost after year 1 MI and stroke.	10/15. However, used resource use estimates determined for a German sample and applied Czech unit costs.
France
2001	Marissal et al.35	Cost analysis	Cost data: from 1994 reimbursement claims for the French national health insurance program converted into per capita 2001 euros. Prevalence: from 1994 analysis of data from the French national health insurance program. Risk of MI and stroke in diabetes: from literature review44. Cost of MI and stroke in diabetics vs non-diabetics: Ramsey et al.45 Final cost estimates were calculated using Monte Carlo simulations based on gamma distributions of the average annual cost of care, the relative risk associated with diabetes, and the prevalence of MI and stroke.	N/A	N/A	N/A	MI and stroke: per capita costs and national costs.	9/15. Resources clearly stated, but unit costs, methods for estimation of quantities, and unit costs not clearly described. Quantities of resource use not reported separately from unit costs.
Germany
2005	Weber et al.46	Retrospective cost study.	Application of unit costs to resource use data collected as part of a retrospective, multi-center study.	Patients with T2DM.	3268 patients	N/A	Per-patient costs in the year of the event: MI and stroke Costs in the year after the event: MI and stroke.	12/15. Not clear on whether all included resource use and unit costs are measured and valued appropriately. No details of productivity change reported.
1998	Liebl et al.36	Cost study	Demographic, socioeconomic, and medical data; complications; and resource utilization retrospectively collected for previous 12 months from patient medical records and interviews with clinicians. Resource use multiplied by price/tariffs and extrapolated to German T2DM population.	Patients with T2DM from CODE-2 study, stratified by complication.	809	N/A	Prevalence of complications (no serious complications; only macrovascular complications; only microvascular or foot complications; patients with both macrovascular and microvascular complications). Resource use, direct and indirect costs total and by complication status. Prevalence/incidence and costs of ulcer/gangrene; amputation and stroke.	14/15. Details of currency of price adjustments for inflation or currency conversion not relevant.
Mexico
2009	Meléndez et al.47	Cost analysis using survey of resource use.	Survey developed to estimate the resource utilization for the treatment of T2DM and administered to specialists.	N/A: survey completed by clinicians.	3 specialists per complication were interviewed.	N/A	Combined cost for years 1 and 2 after complication.	6/15. Resource use estimates based on clinician interviews. Poor reporting of resource use estimates and unit costs. Productivity changes not reported. Major outcomes not reported in disaggregated and aggregated forms.
Spain
2008	Neeser and Weber15	Retrospective chart review.	Review of physician records for demographics and clinical data.	Patients with T2DM.	3268 patients in the ROSSO study.	N/A	Per patient year 1 cost MI and stroke. Per patient cost after year 1 MI and stroke.	10/15. Used data on resource use from German database and applied costs for Spain. Not clear on specific breakdown of costs for complications.
Switzerland
2005	Weber et al.48	Costs for complications referenced to two sources of studies performed in the general population (non-T2DM).	N/A	N/A	N/A	N/A	Year 1 cost for MI and stroke. Cost after year 1 for MI and stroke.	10/15. Used data collected from German databases to provide costs for Switzerland. Unclear reporting of unit costs and resource use.
UK
1999	Clarke et al.2	Cost analysis	Data on hospital inpatient stays collated by each clinic based on patient interviews, death records, and hospital records. Data on non-inpatient healthcare resources collected using a cross-sectional survey of 3488 UKPDS patients. Costs estimated using multiple regression analysis.	Patients with T2DM; mean age, 52.4 years.	5102 patients in the UKPDS study.	N/A	Per patient costs in year of event for MI and stroke.	10/15. Resource use and associated unit costs not reported consistently. Productivity changes not reported. Major outcomes not presented in disaggregated as well as aggregated forms.
US
2000	O’Brien et al.16	Cost analysis using direct data analysis and cost modeling.	Combination of direct data analysis and cost modelling. Patient profiles of resource use determined following review of discharge data.	Patients with T2DM.	Acute MI n = 28,550 Stroke n = 34,823	N/A	MI and stroke: event costs and state costs.	10/15. Time horizon not clear, resources and associated unit costs not clear, productivity costs not included, generalizability of results not discussed.

MI, myocardial infarction; N/A, not available; ROSSO, RetrOlective Study Self-Monitoring of Blood Glucose and Outcome in Patients with Type 2 Diabetes; SMBG, self-monitoring blood glucose; T2DM, type 2 diabetes mellitus; UK, United Kingdom; UKPDS, United Kingdom Prospective Diabetes Study; US, United States.

^aThe appropriateness score was determined from a modified version of the Drummond checklist.

Note: Studies are presented in alphabetical order according to country, and then in chronological order, with the most recent publications first.

Figure 2. Non-fatal myocardial infarction in the year of the event. UK = United Kingdom; US = United States.

Table 2. Annual cost estimates for follow-up subsequent to the first year after a non-fatal myocardial infarction reported in cost studies.

Cost year	Study	Cost of follow-up per patient per MI event (currency)	Cost in 2012 GBP^a	Resources
Canada
2002	O’Reilly et al.7	Can $1338 (Canadian dollars)	945	Inpatient and outpatient costs, emergency room costs, prescription drug costs, long-term care costs, home care services.
1996	O’Brien et al.42	1405 (Canadian dollars)	1456	Accommodation, pharmacy, laboratory, operating room, diagnostic and therapeutic procedures, and physician costs; subsequent sub-acute inpatient care (rehabilitation and long-term care facility); home health and outpatient care (physician visits, medication, and day care).
Czech Republic
2008	Weber et al.27	Kč 5632 (Czech koruna)	286	Not reported.
Germany
2005	Weber et al.46	€1253 (euros)	1131	Not reported.
Spain
2008	Neeser and Weber15	€841 (euros)	845	Not reported.
Switzerland
2005	Weber et al.48	Sw₣ 1823 (Swiss francs)	818	Not reported.
US
2000	O’Brien et al.16	US $1678 (US dollars)	1616	Not reported.

MI, myocardial infarction; OECD, Organisation for Economic Co-operation and Development; UK, United Kingdom; US, United States.

Note: Cost year is the year for which the costs for the event were applied. Studies are presented in alphabetical order according to country.

^aCosts converted to GBP using purchasing-power parity data from the OECD5 and then inflated to UK 2012 prices using Curtis6.

Note: Studies are presented in alphabetical order according to country, and then in chronological order, with the most recent publications first.

Figure 3. Non-fatal stroke in the year of the event. UK = United Kingdom; US = United States.

Table 3. Annual cost estimates for follow-up subsequent to the first year after a non-fatal stroke reported in cost studies.

Country/cost year	Study	Cost per stroke event (Currency)	Cost in 2012 GBP^a	Resources included
Canada
2002	O’Reilly et al.7	Can $9068 (Canadian dollars)	6,405	Inpatient and outpatient costs, emergency room costs, prescription drug costs, long-term care costs, home care services.
2000	O’Brien et al.41	Can $8769 (Canadian dollars)	6,858	Outpatient monitoring; medications (e.g., aspirin); and the increased need for day care, durable medical equipment, and permanent long-term care.
1996	O’Brien et al.42	Can $8141 (Canadian dollars)	7,408	Accommodation, pharmacy, laboratory, operating room, diagnostic and therapeutic procedures, and physician costs; subsequent sub-acute inpatient care (rehabilitation and long-term care facility); home health and outpatient care (physician visits, medication, and day care).
Czech Republic
2008	Weber et al.27	Kč 5632 (Czech koruna)	286	Not reported.
Germany
2005	Weber et al.46	€6501 (euros)	5,983	Not reported.
Spain
2008	Neeser and Weber15	€1911 (euros)	1,920	Not reported.
Switzerland
2005	Weber et al.48	Sw₣ 20167 (Swiss francs)	9,054	Not reported.
UK
1999	Clarke et al.2	£2970 (GBP)	4,704	Hospital inpatient costs.
US
2000	O’Brien et al.16	US $13,419 (US dollars)	12,926	Other care includes all outpatient services for all patients. For those treated initially as inpatients, other care also includes sub-acute inpatient, home health, and day care services where applicable.

GBP, pounds sterling; MI, myocardial infarction; OECD, Organisation for Economic Co-operation and Development; UK, United Kingdom; US, United States.

Note: Cost year is the year for which the costs for the event were applied. Studies are presented in alphabetical order according to country.

^aCosts converted to GBP using purchasing-power parity data from the OECD5 and then inflated to UK 2012 prices using Curtis6.

Note: Studies are presented in alphabetical order according to country, and then in chronological order, with the most recent publications first.

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