Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India

Dr R.R.Sudhir1 DO. DNB. MPH (Johns Hopkins USA)

Head of Dept of Preventive OphthalmologySenior Consultant Cornea Services

Consultant In-charge of EMR

Co-investigators : Sarah Polack2, Rosa Legod2, Yasmene Alavi2, Robert

Lindfield2, Tarun Sharma1, Hannah Kuper1

1Sankara NethralayaMedical and Vision Research Foundation

Chennai, India&

2International Center For Eye Health(London School of Hygiene & Tropical Medicine)

Introduction Diabetic retinopathy (DR) can cause blindness, but this can be

prevented through early detection and treatment. Diabetic populations in rural communities in India typically

have limited access to ophthalmic care. Ensuring regular diabetic ophthalmic examinations for rural

populations therefore poses a considerable challenge. Rural Mobile telescreening for DR provides examination

services for population who may not otherwise have access to them.

Evidence regarding the cost-effectiveness of screening for DR in low income settings is lacking.

Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India Dr R R Sudhir

AIM

To assess the cost-effectiveness of a telescreening of Diabetic Retinopathy program in rural Southern India and to assess the incremental cost effectiveness ratios associated with different screening intervals.

Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India Dr R R Sudhir

Methods We used a Markov model to estimate the cost-utility of

a) the current teleophthalmology program which involves one-off screening in comparison to no screening programme, and

b)the cost-utility of this program at different screening intervals.

Six different screening interval strategies were compared: no screening, once in a life time screening (current approach) and twice in a life time screening, screening every 5 years, 3 years, 2 years and annual screening.

The model was based on a hypothetical cohort of 1000 rural diabetes patients aged 40yrs who had not been previously screened for DR.

Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India Dr R R Sudhir

Methods To estimate utility values associated with DR, 249 people with

diabetes were interviewed using the time-trade off method. Patient and provider costs of screening and treating DR were

estimated through interviews with 100 diabetic patients as well as program and hospital managers.

The sensitivity and specificity of the DR screening was assessed by comparing it to diagnosis using a gold standard method for 346 diabetes patients.

Other model parameters were derived from literature. Incremental cost-utility ratios were calculated from health

provider and societal perspective each successive strategy comparing the most to the next least costly (e.g. comparing annual screening to screening every 2years)..

Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India Dr R R Sudhir

Parameter Baseline Case Sensitivity analysis rangeUtility values    No Diabetic Retinopathy 0.87 0.78-0.97*Mild/moderate NPDR 0.79 0.72-0.86*Sight threatening DR 0.70 0.64-0.77*Bilateral blindness (VA<6/60) 0.55 0.46-0.64*     Annual transition probabilities (4,5,6,7)    

No DR to mild/moderate NPDR 0.06 0.01-0.10¥

Mild/moderate NPDR to STDR 0.06 0.01-0.11¥

MO to blind without laser 0.05 0.03-0.07MO to blind with laser 0.03 0.01-0.05PDR to blind without laser 0.09 0.05-0.11PDR to blind with laser 0.02 0.002-0.03     Prevalence of DR among diabetics 8    

No DR 0.89 0.84-0.93*Mild/moderate NPDR 0.11 0.06-0.16*STDR 0.004 0.0-0.016*

Markov model parameter estimates assumptions

Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India Dr R R Sudhir

Strategy Cost $ Incremental cost QALYIncremental

QALY ICER*

Health provider perspective

No screening 0.0 - 12.6722 - -

Once in a life time 6.5 6.5 12.6771 0.0049 1,320

Twice in a life time 11.7 5.3 12.6810 0.0039 1,343

Every 5 yrs 31.4 19.6 12.6907 0.0097 2,027

Every 3 yrs 48.8 17.4 12.6992 0.0084 2,034

Every 2 yrs 67.2 18.4 12.7067 0.0075 2,435

Annual 118.5 51.4 12.7195 0.0127 4,029

Societal perspective

No screening 0.0 12.6722

Once in a life time 13.2 13.2 12.6771 0.0049 2,692

Twice in a life time 22.9 9.7 12.6810 0.0039 2,475

Every 5 yrs 53.2 30.3 12.6907 0.0097 3,134

Every 3 yrs 81.7 28.4 12.6992 0.0084 3,365

Every 2 yrs 109.4 27.7 12.7067 0.0075 3,669

Annual 181.7 72.4 12.7195 0.0127 5,677

Incremental cost-effectiveness of different tele-screening intervals- comparisons made to next most intensive strategy

Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India Dr R R Sudhir

WHO suggested cost effective range,1-3 times the Indian GDP ($1061-3183).

Discussion The Strength of our study :

Utility value (0.55) derived from a sample of diabetic patients from the program area.

Primary data on costs, effectiveness and diagnostic tool accuracy were collected from the program setting rather than relying on published studies undertaken in other countries.

Data on baseline DR prevalence was estimated from a recent population based study conducted in Chennai.

Limitation : Our model assumed 100% attendance of the initial cohort at each subsequent DR screening. Although there is evidence that DR screening in rural communities may increase compliance compared to hospital based screening, complete attendance may not be realistic.

Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India Dr R R Sudhir

Conclusion

Our analysis suggests that a one-off telescreening program for DR is cost-effective compared to no screening in this rural Indian setting from a health provider perspective.

Increasing the frequency of screening up to 2 years is also cost-effective, although this is dependent on the administrative costs of establishing and maintaining screening at regular intervals and on achieving sufficient coverage

Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India Dr R R Sudhir

Cost Utility of Mobile Telescreening of Diabetic Retinopathy in rural south India Dr R R Sudhir

Thank youAcknowledgements

Study Grant : Sight Savers International