Table 2 Summary of included studies
| Â | Model (reference) | Intervention and setting | Main outcome(s) | Modelling approach/ framework, time horizon and cycle | Data sources | |||
|---|---|---|---|---|---|---|---|---|
Disease onset, progression and mortality data | Intervention effectiveness | Utilities/outcomes measure | Costs | |||||
Primary prevention | Zhang, Kivipelto [26] | Hypothetical intervention reducing risk of AD onset in Sweden | QALYs | Purpose-built Markov model with 3 health states. 20-year time horizon, 1 year cycles | CAIDE population based study on risk factors of 1409 individuals [44] | Hypothetical intervention | Swedish National Board of Health and Welfare | |
Tsiachristas & Smith [32] | Preventative treatment with B-vitamin supplement for people aged 60 and over with elevated levels of tHcy in the UK | Life-Years; QALYs | Stochastic probabilistic decision tree; lifetime horizon. | Disease progression not modelled. Disease onset based on prevalence data; mortality from life tables. | Effectiveness of intervention based on a systematic review in lieu of randomised controlled trials [37] | General population EQ5D survey [36] | Taken from a UK study [58] | |
Secondary prevention | McMahon [28] | Functional neuroimaging vs. standard work-up of patients for AD diagnosis at specialised AD clinics in the US | QALYs | Markov model based on a previously published study [40]; 6-week cycles, 18-month time horizon. | Progression within AD and AD mortality from CERAD study [40]. Non-AD mortality from CDC. | Screening effectiveness from US-based study [59] | Utility weights obtained from the Neumann et al. [40] | Primary data from hospital databases; existing literature |
Silverman, Gambhir [31] | PET vs. standard diagnostic methods in clinical diagnosis of AD in the US | Number of accurate diagnoses | Purpose-built decision-tree, unspecified time horizon | Adapted from a wide range of published data | Results of PET screening reported in the study | Not used - CEA | Defined by Medicare reimbursement rates | |
Weimer and Sager [30] | Early detection and treatment of AD patients in a US (Wisconsin) setting. Two treatments considered. | MMSE score change | Monte Carlo model. Lifetime horizon, 1 year cycles | Adapted from a range of published data and estimates. Data from CVD risk study on 5000 people was used to estimate hazard ratio for death. | A range of published data and estimates | Adapted from [40] | A range of published data and estimates | |
Dixon, Ferdinand [35] | One-off screen of 75 year olds in England and Wales | Number of additional diagnoses | Static decision model with lifetime time horizon | Not provided | Results of screening based on MMSE (assumed 89% sensitivity, 95.5% specificity) | Not used – CBA | A range of published data and estimates | |
Saito, Nakamoto [27] | Community based dementia screening in a US setting | Dementia diagnosis through MMSE | Purpose-built Markov model with 6-state 10-year time horizon, 1 year cycles | Adapted from [46, 48] which investigated 61 and 1145 patients, respectively | Results of screening program reported in study | Not used - CEA | Adapted from a Canadian study [60] | |
Tertiary prevention | McDonnell, Redekop [33] | A hypothetical intervention which slows cognitive decline in AD patients in the Netherlands | MMSE score change, care setting, mortality | Two regression-based simulation models – one modelling MMSE score, another- care setting and mortality. 10-year time horizon, 6 month cycles | Calculated from a Dutch study [38] with 7528 participants. | Hypothetical intervention | Not used – CEA | From Dutch national data, agencies/ ministries |
Martikainen, Valtonen [29] | Cognitive-behavioural family intervention to delay admission to nursing home in Finland | Time to nursing home admission | Markov model. Adapted from [40]. Model has 4 states, 5-year time horizon, 1 year cycles | Adapted from the original US-based model (with minor adjustments) – based on longitudinal study with 1145 patients [40] | Based on a US study of 206 subjects [61] | From the original US-based model | From national datasets; some resource utilisation based on expert panel | |
Mirsaeedi-Farahani, Halpern [34] | Deep-brain stimulation therapy for slowing memory loss in AD patients compared to standard treatment | QALYs | Purpose-built Markov model with 5 states, 5-year horizon, 1 year cycles | Actual success rate of deep brain stimulation is unknown, so was varied from 0 to 100% | A range of published data | Costs obtained from [62] | ||