Data collection and information management RAABs: How frequently should these be done at national or sub-national level? Hans Limburg, MD PhD, DCEH

RAAB Rapid Assessment of Avoidable Blindness –Population-based, representative survey –Standardised method: comparable worldwide –Accuracy depends on sample size Purpose –Baseline data for planning PBL programmes –Evaluation of ongoing PBL programmes Cost –Standard RAAB (ss 3000: US$ 20,000 – 40,000) –RAAB + DR: twice as much

Main results from RAAB Prevalence of blindness, SVI, MVI Prevalence of low vision Causes of blindness, SVI, MVI Prevalence of cataract (BCVA<3/60, <6/60, <6/18) Cataract surgical coverage Visual outcome after cataract surgery Barriers to cataract surgery Age & sex adjusted prevalence, estimated cases Age at time of surgery; place of surgery; cost; cause of poor outcome

Where surveys were done RAABRACSS Custom survey

Where surveys were done RAABRACSS Custom survey

Where surveys were done RAABRACSS Custom survey

1999: Paraguay 2002: Peru 2003: Argentina 2003: Brazil 2004: Venezuela 2004: Guatemala 2004: Cuba 2006: Mexico 2007: Chile 2008: Colombia 2001: Turkmenistan 2001: Mauretania 2001: Mali 2003: Nigeria 2005: Kenya 2006: Rwanda 2007: Kenya 1995: India : Vietnam : Cambodia : Pakistan 2004: Indonesia 2004: Myanmar : Philippines 2005: Bangladesh 2006: China 2007: Vietnam : Cambodia 2007: Laos 2007: China 2008: China 2008: Nepal : The Gambia 2007: Tanzania 2007: Zanzibar 2007: Uganda 2008: Palestine 2008: Mali 2008: Eritrea RACSS RAAB RACSS and RAAB conducted

‘Repeat’ surveys CountryYearBlindness PVA<3/60 Cataract blind CSC Persons; <3/60 Nepal %0.6%35% BCVA<3/60; all ages %0.2%85% Kolar dist %5.7%46% PVA<3/60; %2.2%86% Paraguay %2.0%44% PVA<3/60; %0.3%90% Cambodia: 2000 and 2007: different survey areas Peru: 2002 and 2011: different survey areas

RAAB in Vietnam 2002 and 2007 (prevalence and 95% confidence interval)

RAAB : ideal frequency? Capacity to detect significant change Conditions comparable –Same survey area –Same survey protocol, age groups, definition Depending upon sample size –Large sample  narrow confidence interval Depending on intervention activities –5-7 years for very active programmes –8-12 year for less active programmes

Web-based repository for RAABs Year conducted Survey area Reference to publication Name and address Principal Investigator Downloads (only with permission from PI) –Zip-file with all reports –Cleaned data as Excel file