Table 1 Characteristics of included studies
From: The financial burden of diabetes-related foot disease in Australia: a systematic review
Study information | |||||||||||||||||
Author (Year) | Study design | Sample Size | Study population / setting | Inclusion / exclusion | Aims / objectives | Intervention / comparator | Study outcomes | Model description | Statistical analysis | ||||||||
Cheng et al. (2017) [22] | Cost-effectiveness analysis | Hypothetical cohort of people with DM at high risk of DFU Cohort based on patients registered with the National Diabetes Services Scheme (2015) in Australia | Simulated cohort of people with DM at high risk of developing DFUs in Australia Simulations were separated for differing age groups. The distribution of diabetes among the age groups was informed by the Australian Health Survey 2011–2014 | People with DM at high risk of DFU (i.e. those with previous DFU or amputation) | To examine the costs and health outcomes associated with implementing optimal guideline-based care compared with usual care in people at high risk of DFUs in Australia | Optimal care: Components of foot examination, debridement, wound dressings, pressure offloading, infection management and multidisciplinary care Usual care: A mix of largely uncoordinated set of services in the community | Expected costs, cost-effectiveness and QALYs associated with optimal care versus usual care | Markov model: - 5-years - 1-month cycles - 60 cycles in total - 7 possible health states | - Markov model - Scenario analysis - Probabilistic sensitivity analysis | ||||||||
Graves and Zheng (2014) [25] | Economic evaluation | 12,839 (SD, 3,534) cases of DFU in all hospitals in Australia 516 (SD, 141) cases of DFU in residential care setting in Australia | Cohort of patients with pressure ulcer, DFU, venous ulcer or artery insufficiency ulcer located in hospital and residential care settings in Australia for 2010–2011 | People with either a pressure ulcer, DFU, venous ulcer or artery insufficiency ulcer | To estimate the direct healthcare costs of chronic wounds in hospital and residential care settings in Australia | Not applicable | Direct healthcare costs of chronic wounds in hospital and residential care settings | Probabilistic model to estimate direct healthcare costs | - Probabilistic analysis | ||||||||
Zhang et al. (2023) [26] | Cost-effectiveness analysis | Overall cohort of patients with DFU (n = 3,385) who presented to Diabetic Foot Services in Queensland, Australia followed up for at least 3 years Model included 3,122 patients with care data to derive the events and corresponding time-to-event parameters | A prospective cohort of patients with DFU attending multi-site outpatient Diabetic Foot Services in Queensland, Australia between 1/7/2011 to 1/6/2016 | People with DFU attending Diabetic Foot Services | Primary aim: To estimate the costs and QALYs associated with complete adherence to guideline-based care, compared with current practice Secondary aim: To estimate the costs, cost-effectiveness and QALYs associated with increasing levels of guideline-based care, compared with current practice | Guideline-based care: Components of foot examination, debridement, wound dressings, offloading, infection management and multidisciplinary care Current practice (sub-optimal care): 30% of patients receiving guideline-based care and 70% receiving sub-optimal care (i.e. all other care that does meet the definition of guideline-based care) | Expected costs, cost-effectiveness and QALYs associated with guideline-based care versus current practice (i.e. sub-optimal care) | Discrete event simulation model - 3-years - 6 possible health states | - Discrete event simulation model - Parametric survival analysis - Probabilistic sensitivity analysis | ||||||||
Participant characteristics | |||||||||||||||||
Author (Year) | Age | Sex | Diabetes type/duration | Comorbidities | Clinical state of DFD | Ulcer characteristics | |||||||||||
Cheng et al. (2017) [22] | Age groups (years): - 35–54 - 55–74 - 75 +  | Not reported | Not reported | Not reported | Markov model health states included: no DFU, uncomplicated DFU, complicated DFU with infection, post minor amputation, infected post minor amputation, post major amputation, and death | As per the health states used in the Markov model | |||||||||||
Graves and Zheng (2014) [25] |  ≥ 15 years for hospital separations  ≥ 65 years for aged care residents | Not reported | Not reported | Not reported | Not reported | Not reported | |||||||||||
Zhang et al. (2023) [26] | 62 (SD, 13) years | Male: 2,350 (69.4%) Female: 1,035 (30.6%) | Type 1 DM: 314 (9.3%) Type 2 DM: 3,071 (90.7%) Diabetes duration: 16.4 (SD, 10.7) years HbA1c: 8.52 (SD, 2.44) | DM, hypertension, dyslipidaemia, CVD, CKD, ESRD, smoking | Markov model discrete episodes of disease included: healed DFU, recurrent DFU, hospitalisation (no amputation), minor amputation, major amputation, and death | Ulcer size:  < 1cm2 = 1,559 (46.1%) 1-3cm2 = 643 (19.0%)  > 3cm2 = 551 (16.3%) Deep ulcer: 518 (15.3%) Infection: Nil = 2,226 (65.8%) Mild = 753 (22.2%) Moderate to systemic = 405 (12.0%) | |||||||||||
Cost of DFD | |||||||||||||||||
Author (Year) | Type and frequency of treatments | Provision of treatment | Unit costs of treatment / model inputs | Data sources | |||||||||||||
Cheng et al. (2017) [22] | Usual care: If ‘uncomplicated DFU’, patients assumed to receive: - One-off initial assessment by GP for risk of amputation - Medical checks by GP twice weekly - Absorbent wound dressing changes twice weekly - Post-operative boots If ulcer heals, patients assumed to receive no further care If ‘complicated DFU with infection’, patients assumed to receive: - Pathology services - Systemic antimicrobials Optimal care: Defined according to the National evidence-based guideline on prevention, identification and management of foot complications in diabetes [28] If ‘uncomplicated DFU’, patients were assumed to receive: - One-off initial assessment to grade DFU severity by both a podiatrist and GP - Wound debridement weekly - Wound dressing changes consisting of soft-gelling cellulose fibre and polyurethane foam twice weekly - Irremovable pressure offloading device during treatment - Multidisciplinary care from both podiatrist and GP trained in wound management weekly If ulcer heals, patients were assumed to receive: - Podiatry consultations every 2 months - One pair of extra-depth footwear per year - Patient education If ‘complicated DFU with infection’, patients were assumed to receive: - Pathology services - Topical and systemic antimicrobials - Diagnostic imaging to evaluate suspected osteomyelitis | Consultations with a GP, podiatrist and/or multidisciplinary care team | Usual care: Ongoing costs according to health states (community) No DFU = $0 Uncomplicated DFU = $302.64 Complicated DFU with infection = $315.83 Post minor amputation = $1,797.50 Post major amputation = $4,934.30 Infected post minor amputation = $315.83 Initial costs according to health states (community) Uncomplicated DFU = $67.05 Complicated DFU with infection = $100.80 Optimal care: Ongoing costs according to health states (community) No DFU = $45.80 Uncomplicated DFU = $504.80 Complicated DFU with infection = $829.59 Post minor amputation = $1,843.30 Post major amputation = $4,934.30 Infected post minor amputation = $829.59 Initial costs according to health states (community) Uncomplicated DFU = $296.80 Complicated DFU with infection = $769.90 Transition costs (hospital): Minor amputation = $10,640 Major amputation = $23,921 Infected DFU = $16,354 Infected post minor amputation = $25,108 | - Australian and international literature - Medicare Benefits Scheme - Pharmaceutical Benefits Scheme - Australian Refined Diagnosis Related Group codes - Expert opinion | |||||||||||||
Graves and Zheng (2014) [25] | Direct healthcare costs of chronic wounds in hospital and residential care settings in Australia | Australian hospitals and residential care settings | Based on previous studies, minimum and maximum healthcare costs of DFU in the hospital setting were $5,029 and $32,242, respectively Due to a lack of data, the healthcare costs of DFU in the community setting were used for the residential care setting (i.e. previous studies report costs between $20,343 and $22,310) | - Australian and international literature - Australian Hospital Statistics 2010–2011 - Diabetes Hospitalisations in Australia 2003–2004 - Australian demographic statistics 2011 - Australian residential aged care statistical review 2010–2011 | |||||||||||||
Zhang et al. (2023) [26] | Current practice (sub-optimal care): Defined as not meeting criteria for guideline-based care DFU episode One-off costs: Post-op shoe Ongoing costs: Wound management, wound dressing, antibiotics Healed DFU One-off costs: $0 (patients wear their own shoes) Ongoing costs: Wound management Guideline-based care: DFU episode Frequent (≤ 21 days since the previous visit) evidence-based DFU classification documented for 100% of visits in the episode; plus receiving sharp debridement, appropriate wound dressing, antibiotics prescribed (if DFU classified as infected), and knee-high pressure offloading devices during at least 75% of all clinic visits throughout the episode One-off costs: Knee-high removable cast walker offloading device Ongoing costs: Wound management, wound dressing, antibiotics Healed DFU Regular (≤ 100 days since the previous visit) evidence-based foot monitoring documented for 100% of visits in the episode; plus receiving sharp debridement, and appropriate footwear during at least 75% of all clinic visits throughout the episode One-off costs: Medical grade extra depth footwear Ongoing costs: Wound management | Diabetic Foot Services | Current practice (sub-optimal care): DFU episode One-off costs: Post-op shoe ($30) Ongoing costs: Wound management ($186), wound dressing ($1.56), antibiotics ($35.08) x2 Average outpatient care costs per week: $176.10 (SD, 185.70) Healed DFU One-off costs: None Ongoing costs: Wound management ($186) Average outpatient care costs per week: $71.90 (SD, 85.10) Guideline-based care: DFU One-off costs: Knee-high removable cast walker offloading device ($197) Ongoing costs: Wound management ($186), wound dressing ($11.40), antibiotics ($35.08) × 2 Average outpatient care costs per week: $310.50 (SD, 236.70) Healed DFU One-off costs: Medical grade extra depth footwear ($176) Ongoing costs: Wound management ($186) Average outpatient care costs per week: $124.90 (SD, 112.40) Event costs, inpatient (per event): Hospitalisation – $15,477 (SD, 14,839) Minor amputation – $30,530 (SD, 14,059) Major amputation – $47,327 (SD, 15,503) | - Australian and international literature - Pharmaceutical Benefits Scheme - Australian Refined Diagnosis Related Group codes - Independent Hospital Pricing Authority - Expert opinion | |||||||||||||
Economic evaluation characteristics | |||||||||||||||||
Author (Year) | Study perspective | Time horizon | Discount rate | Reporting of costs | Type of model | Costs included | Measures of health benefit and cost-effectiveness | Expected cost savings and health benefits | Overall economic evaluation | ||||||||
Cheng et al. (2017) [22] | Health system perspective | 5 years | 5% | AUD 2013 | Markov model | Consultations with a GP, podiatrist and/or multidisciplinary care team, consumables (e.g. scalpel blades for debridement, wound dressings), pressure offloading devices (e.g. Aircast), footwear, pathology, radiology, antimicrobials, and hospital costs associated with minor or major amputations (e.g. home care, prostheses, inpatient and outpatient care) | QALYs | Overall 5-year cost saving ($9,100 for 35–54 years, $9,392 for 55–74 years and $12,395 for 75 + years) Overall 5-year improved health benefits (0⋅13 QALYs for 35–54 years, 0⋅13 QALYs for 55–74 years and 0⋅16 QALYs for 75 + years) | Cost saving Optimal care dominant in each age group compared to usual care | ||||||||
Graves and Zheng (2014) [25] | Not reported | Not reported | Not reported | USD 2012 | Probabilistic model | Hospital separations | Not applicable | Not applicable | Not applicable | ||||||||
Zhang et al. (2023) [26] | Health system perspective | 3 years | 5% | AUD 2020 | Discrete event simulation model | Two categories of costs were considered: (i) average weekly episode care costs (for active DFU or healed DFU) in the outpatient Diabetic Foot Services including healthcare consultations, consumables (such as dressings), pressure offloading devices, footwear and antibiotics and (ii) event costs for hospitalisation (no amputation) and minor / major amputation procedures within the inpatient setting | QALYs ICER NMB | Overall 3-year cost saving of $1,843 and 0.056 QALY per person for 100% guideline-based care, dominating current practice with a NMB of $3,420 Remaining scenarios (40% to 90% guideline-based care) were also dominant relative to current practice with average cost savings between $278 to $1,381 per person (0.011 to 0.045 QALYs) | Cost saving All proportions of guideline-based care (40%-100%) were dominant relative to current practice | ||||||||