Exercise on TB clinical epidemiology: what are the indicators suggesting? G.B. Migliori WHO Collaborating Centre for Control of TB and Lung Diseases, Fondazione S. Maugeri, IRCCS, Tradate, Italy G. Sotgiu Hygiene and Preventive Medicine Institute University of Sassari Medical School, Italy

Learning Objectives To discuss the meaning of the main outcome indicators To interpret what indicators are suggesting To use evidence from data to take decisions

TB TRANSMISSION MODEL 1 SOURCE 20 INFECTED 10 INFECTIONS X 2 YRS = 20 10% LIFETIME BREAKDOWN 50% SMEAR POSITIVE IN ABSENCE OF INTERVENTIONS

TB TRANSMISSION MODEL 5 INFECTED 10 INFECTIONS X 0.5 YR = 5 10% LIFETIME BREAKDOWN 50% SMEAR POSITIVE WITH EARLY DIAGNOSIS & TREATMENT 1 SOURCE 0.25 SOURCE

TB TRANSMISSION MODEL 30 INFECTED 10 INFECTIONS X 3 YRS = 30 10% LIFETIME BREAKDOWN 50% SMEAR POSITIVE WITH IRREGULAR TREATMENT 1 SOURCE 1.5 SOURCES

NTP Targets To cure 85% of sputum smear positive tuberculosis cases detected and To detect 70% of the estimated new sputum smear positive tuberculosis cases

70/85: the best compromise to achieve 40% reduction in transmission success rate > CDR, < success rate 40% reduction in transmission

Results expected in a good programme Success rate > 85% If mathematics are not an opinion, we have max 15% for negative outcomes: Death rate < 5% Other unsatisfactory outcomes (Default, Failure) < 10%

What are the targets suggesting? Case finding: < 70% = 70% > 70%

What are the targets suggesting? Treatment outcomes: Success > 85% Success 75-85% Success < 75% Different combinations of cure and treatment completion

What are the targets suggesting? Other outcomes: high/ low default rate high/ low death rate high/ low failure rate high/ low transfer-out rate

Fictitia

Yahoo Oblast DOTS newly implemented Case detection: 50% 30% are SS+, 15% culture + cases Success 80% (60% cure; 20% completion) Failure 5%; Death 7%; Default 8% What do you need to ask/ investigate/ check?

Wanadoo Oblast DOTS implemented since 3 years Case detection: 70% 70% bacteriologically confirmed Success 88% (85% cure; 0% completion) Failure 0%; Death 8%; Default 4% What do you need to ask/ investigate/ check ?

Tiscali Oblast DOTS implemented since 1998 Case detection: 60% 95% are SS+ Success 80% (75% cure; 5% completion) Failure 5%; Death 4%; Default 11% What do you need to ask/ investigate/ check ?

Hotmail Oblast DOTS implemented since 1998 Case detection: 60% 95% are SS+ Success 75% (55% cure; 20% completion) Failure 5%; Death 12%; Default 8% What do you need to ask/ investigate/ check ?

Asianet Oblast DOTS implemented since 5 yrs Case detection: 50% 20% are SS+ and/or culture + cases Success 60% (30% cure; 30% completion) Failure 8%; Death 12%; Default 15% Transferred out 5% What do you need to ask/ investigate/ check ?