Application of the Onion model to assess

the extent of missing tuberculosis cases

by the National Programmes

Dr Amal Bassili

Stop TB unit, WHO, Regional Office for the Eastern Mediterranean

Surveillance Workshop

Cairo Sheraton

Cairo, Egypt, 27-29 October, 2009

2/3/2010 1

Background

• In 2007, the estimated number of smear positive

pulmonary tuberculosis was 259,885 cases while

the notified number of cases was 155, 481

• The Region achieved a case detection rate (CDR)

of 60% and did not achieve the global target of

70%

• This would mean that as many as 103,954 smear

positive TB patients (i.e. 40% of the total) may

not have had access to appropriate TB care

2/3/2010 2

Background: Causes of low case

detection

• Suboptimal quality of TB care: for example,

– laboratory diagnosis is not always extensive or accurate.

– Management of TB suspects is not yet well established.

– Health care providers in public and private sectors are not fully involved.

– Complex emergencies are affecting TB care in countries particularly those with a high burden of TB.

– Awareness of TB is not always high in the community, and TB is often heavily stigmatized.

– the care-seeking behavior of patients and the health systems responses are extremely dynamic and complex, and do not follow any stereotyped patterns.

2/3/2010 3

Methodology of the guide • A guide with a stepwise approach was developed aiming at

evaluating the efficiency of case finding activities.

• This guide was tested and then used in several programme review missions in the countries of the EMR. The approach is based on the patient’s pathway to care from the community to the diagnostic and treatment centres for TB.

• The below hypothetical Onion-shaped model depicts this approach. Each layer of this “Onion” describes one step taken by the patient, from outer-most layer to inner-most layer, in the pathway to care and also indicates the relevant programmatic activities according to the Stop TB strategy.

2/3/2010 4

2/3/2010 5

Diagnosed & reported

cases by TBMU

Step 1: ACSM

Step 2: Public-Private mix, Suspect management

Step 3: Public-Public mix, Suspect management

Step 4: Suspect management

Step 5:Laboratory diagnosis

Step 6:DOT with Treatment supportMonitoring and Evaluation Drug managementContact managementHIV/TBMDR-TB

Undetected cases at

laboratory of TBMU

Undetected cases at out-

patient units of TBMU

Undetected cases at

public health facilities

Undetected cases at

private health facilities

Undetected TB cases

in community

Estimated

TB incidence

Onion model to detect the undetected TB cases

Methodology of the guide • In order to measure the performance of activities in

the layers of the model, a set of indicators was developed for each layer of the model

• All the indicators were reported in the WHO compendium of indicators.

• Several sources were used to collect the necessary data: – Global TB Data Collection Form of WHO,

– programme review mission reports,

– countries’ reports,

– operational research studies, and

– the web-based quarterly reporting system from the countries of the Region to the WHO EMRO, the “EMRO DOTS Quarterly online (DQ online).”

2/3/2010 6

Methodology of the guide

– For each step, the recommended level (target)

was in principle defined and the performance of

the indicator was evaluated using a 4-point Likert

scale (1 worst and 4 best)

– If the indicator could not be evaluated due to lack

of information or due to the absence of the

related activities, a “zero” score was given.

2/3/2010 7

Methodology of the guide • All the indicators were given the same weight except the following:

– TB suspect register coverage, and the treatment success rate. These were given double weight.

• a good coverage of suspect register in the TBMUs and PHCs enhances timely identification of TB suspects at their first point of care in the health system.

• successful treatment is the most effective measure to control the disease. While this indicator is not implicated in the case finding process, it is strongly correlated with the programme performance .

– The sale of anti-TB drugs in private pharmacies was given a triple weight, provided it is supported by evidence. Experience has shown that, whenever the sale of anti-TB drugs is banned in the private pharmacies, the non-NTP providers refer their diagnosed cases to be treated at the NTP.

• This situation proved to be the most effective intervention to detect almost all cases in the country, especially, in the presence of good community accessibility to public health services.

2/3/2010

Methodology of the guide

• The percentage summation score for each component and all the components was calculated as follows: (Sum of scores obtained/Maximum scores that could be

obtained) X 100.

• Then the percentage summation score of the studied component and all the components was expressed as falling between 0 and 100%, with the highest percentage reflecting a better performance related to that component.

• The 95% confidence interval (CI) around the proportion was calculated. Data analysis was performed using excel.

2/3/2010 9

Application of the methodology

The model with its indicators was applied in 3

countries of the Region:

Jordan, Syria and North Sudan

2/3/2010 10

1. ACSM

Indicators

Target Measurement Wt Score

1

Score 2 Score 3 Score 4

Use of TV, radio,

print media as

communication

tool

To become the

source of

information for

the community

No. of TV or radio

announcements, or

printed media

1 None printed

materials

Additiona

l media

activities

Full strategy

implemented

Knowledge about

TB among TB

patients and

community

Improved over

time

Proportion of

individuals with

correct knowledge

about TB

1 <25% 25-50% 50-75% >75%

Level of stigma

related to TB

among TB

patients and

community

Reduced over

time

Mean percent score of

stigma related to TB

1 >75% 50-75% 25-50% <25%

Patient delay Reduced over

time (target 2

weeks)

Duration between the

onset of symptoms and

their first visit to

health facilities

1 Mean

≥≥≥≥60day

s

Mean

31-60

days

Mean

14-30

days

≤≤≤≤2 weeks

First care-seeking

behavior of

patients

TB centres

(TBMUs or

PHCs)

Proportion of patients

that visited TB centres

1 <25% 25-50% 50-75% >75%

Civil society

engagement

Increased over

time

% of patients

supported by NGO

1 0-25% 25-50% 50-75% >75%

2/3/2010 11

Indicators Jordan

2007-2008

Score Syria

2007-2008

Score North Sudan

2007-2008

Score

Use of TV, radio, print

media as communication

tool

Limited to printed

materials

2 Limited to

printed

materials

2 Limited to

printed

materials

2

Knowledge about TB

among TB patients and

community

79% of TB suspects in

the community had

adequate knowledge

about TB

4 61% of patients

had adequate

knowledge

about TB.

3 50.5% had

adequate

knowledge

about the

disease

3

Level of stigma related to

TB among TB patients

and community

Mean percent score 71%

for TB suspects in the

community

2 High among

patients but not

yet studied in

the community

2 The average

score of stigma

in the

community was

54.7% in 2008

2

Patient delay (duration

between onset of

symptoms till their first

visit)

Mean of 7.4(3.9) days for

TB suspects in the

community

4 -Mean

(SD)=80.4(79.0)

1 69.7(28.1) in

2006

1

First health seeking

behavior of patients

Public health centres for

92% of the community

living at >30 km from the

TB centre, followed by

the private sector

4 Public health

centres for 21%

of patients

1 Public health

centres for 90%

of community

4

Civil society engagement

(% of patients supported

by NGOs)

>75% 4 25-50% 2 <25% 1

2/3/2010 12

2-3 PPM

Indicators

Target Measurement Weight Score 1 Score 2 Score 3 Score 4

Presence of PPM

focal person, task

force and

guidelines

Yes Present or not 1 None Focal

point

Focal

point and

guidelines

Focal

point, task

force and

guidelines

Non-NTP facilities

engaged out of

planned

100% No. of non-NTP health

facilities participating in

TB care (DOTS) / Total no.

of targeted (X100)

1 0-25% 25-50% 50-75% >75%

% of suspects

referred from

private and public

non-NTP sector

Increase

over time

No. of suspects referred

from non-NTP providers /

total number of suspects

identified by NTP(X100)

1 0-10% 10-25% 25-50% >50%

% of TB cases

detected by public

and private non-

NTP provider

Increase

over time

Number of TB cases

detected by non-NTP

providers/total number of

cases (X100)

1 0-10% 10-25% 25-50% >50%

Sale of TB Drugs

in private

pharmacies

No Extent of sale of anti-TB

drugs in private pharmacies

3 >50% of

population

25-50% of

population

5-25% of

population

No or

negligible

(<5%)

No. of training

sessions for PPM

out of planned

100% No. of training sessions /

total planned (X100)

1 0-25% 25-50% 50-75% >75%2/3/2010 13

Indicators Jordan

2007-2008

Score Syria

2007-2008

Score Sudan

2007-2008

Score

Presence of PPM focal

person or task force and

guidelines

Yes 4 Yes 4 Yes, newly

appointed,

guidelines

developed in 2009

1

Non-NTP facilities

engaged out of planned

100% 4 1160 out of a total of

1540 public health

facilities (75%). All the

162 (100%) private health

facilities are engaged.

4.00 184 out of a total of

443 public health

facilities (41.5%).

The private sector

engaged is

negligible.

2

% of suspects referred

from public and private

sector

58% 4 6858 out of a total of

12,498 suspects (54.9%)

were referred from public

and private non-NTP

providers

4.00 Data not available 0

% of TB cases detected

by public and private

non-NTP providers

66% 4 66% from private and

19% from public

4.00 4% from public

sector and none

from the private

sector

1

Sale of TB Drugs in

private pharmacies

None 12 None 12 Yes 3

No. of training sessions

and trained personnel

for PPM

<25% of

planned

1 <25% of planned 1 <25% of planned 1

2/3/2010 14

4 Suspect

management

Indicators

Target Measurement Weight Score 1 Score 2 Score 3 Score 4

% of suspects that

have had sputum

smear examination

100% No. of suspects who

had their sputum

examined at

laboratory / No. of

suspects identified

at outpatient units

(X100)

1 <75% 75-90% 90-95% >95%

% of suspects

diagnosed as sputum

smear positive TB

≈≈≈≈10% No. of suspects with

positive smears /

total no. of

suspects(X100)

1 >20% 15-20% >10-15% ≤≤≤≤10%

TB suspect register

coverage in the

outpatient

departments (TBMUs

and PHCs) (or PAL

coverage including

the use of suspect

register)

100% No. of outpatient

departments

(TBMUs and PHCs)

with suspect

registers / all

outpatient

departments (X100)

2 0-25% 25-50% 50-75% >75%

2/3/2010 15

Indicators Jordan

2007-2008

Score Syria

2007-2008

Score Sudan

2007-2008

Score

% of suspects that have

had sputum smear

examination

100% 4 95% 4 NA 0

% of suspects

diagnosed as sputum

smear positive TB

5.1% 4 7% 4 NA 0

% of health facilities

with TB suspect

register (TBMUs and

PHCs) /PAL activity

coverage including

suspect register

100% 8 in TBMUs only 6 None 0

2/3/2010 16

5 Laboratory

Indicators

Target Measurement Weigh

t

Score 1 Score 2 Score 3 Score 4

Size of population per

functioning diagnostic

laboratory

(microscopy)

1 lab

per 50-

250,000

populat

ion

Total population / No.

of functioning

diagnostic laboratories

1 1 lab per

>550,000

pop

1 lab per

300,000-

550,000

pop

1 lab per

250,000-

300,000

pop

1 lab per

<250,000

population

Extent of EQA

coverage for direct

smear microscopy

100% No. of diagnostic units

submitting slides for

EQA / Total no. of

diagnostic units (X100)

1 <50% 50-75% 75-99% 100%

Proportion of

microscopy

laboratories that

failed to show

adequate performance

0% No. of laboratories

that reported major

error (high false

positive (HFP) or high

false negative (HFN)) /

No. of laboratories

covered by the EQA

system (X100)

1 >10% 5-10% 1-5% 0%

2/3/201017

5 Laboratory

Indicators

Target Measurement Weigh

t

Score 1 Score 2 Score 3 Score 4

Proportion of lab

personnel trained out

of planned

100%

% of lab personnel

trained

out of planned

1 <50% 50-75% 75-99% 100%

% of supervisory

visits with feedback

reports to lab out of

planned

100% No. of supervisory

visits conducted / No.

of supervisory visits

planned (X100)

1 <50% 50-75% 75-99% 100%

Primary defaulter rate 0% No. of SS+ cases

detected at laboratory)

– (No. of smear

positive TB cases

registered for

treatment) / No of SS+

cases detected at

laboratory (X100)

1 >10% 5-10% 1-5% 0%

Proportion of smear

positive cases among

all pulmonary TB

cases

60-70% No. of smear positive

TB cases / No. of all

pulmonary TB cases

(X100)

1 <40% 40-50% 50-60% >60%

2/3/201018

Indicators Jordan

2007-2008

Score Syria

2007-2008

Score Sudan

2007-2008

Score

Laboratory network coverage:

Number of population per

functioning diagnostic

laboratory (microscopy)

1 per 39,000 4 1 per

300,000 pop

3 1 lab per

120,372

population

4

Extent of EQA coverage for

direct smear microscopy

8% 1 14/65

(21.5%)

1 53% 2

Proportion of microscopy

laboratories that failed to

show adequate performance

0% 4 22% in 2008 1 60% 1

% of lab personnel trained out

of planned

50-75% 2 88% 3 <50% 1

% of laboratories supervisory

visits with feedback report

50-75% 2 80% 3 Inadequate

(less than

1/lab/year)

1

Primary defaulter rate 0% 4 0% 4 Up to 50%

in some

centres

1

Proportion of smear positive

cases among all pulmonary TB

cases

71% 4 62% 4 55.1% 3

2/3/2010 19

6 Quality of NTP

surveillance and case

management

Target Measurement Weight Score 1 Score 2 Score 3 Score

4

Report completeness 100% Number of submitted

reports from

TBMU/number of

expected reports (X100)

1 <50% 50-

75%

75-

99%

100%

Direct observation of

treatment (DOT)

100% No. of patients daily

supervised during the

entire treatment

period/ total no. of

cases treated(X100)

1 <50% 50-

75%

75-

99%

100%

Adherence to

standardized

treatment regimens

100% No. of cases treated

with correct treatment

regimens / Total no. of

cases eligible to the

regimen (X100)

1 <50% 50-

75%

75-

99%

100%

Treatment success

rate

>85% No. of smear positive

TB patients successfully

treated / No. of patients

registered (X100)

2 <75% 75-

80%

80-

85%

>85%

% of annual

supervisory visits with

feedback reports out

of planned at all levels

100% No. of supervisory visits

with feedback reports

at all levels/total No. of

planned visits at all

levels(X100)

1 <50% 50-

75%

75-

99%

100%

2/3/201020

6 Quality of NTP

surveillance and case

management

Target Measurement Wt Score 1 Score 2 Score 3 Score

4

% household contact

evaluated for TB (all

ages)

100% No. of household

contacts evaluated for

TB/ total No. of

household contacts

(X100)

1 <50% 50-75% >75-

95%

95-100%

% household contact

evaluated for TB

(under 5 years of age)

100% No. of household

contacts under 5

evaluated for TB/ total

No. of household

contacts under 5 years of

age

1 <50% 50-75% >75-

95%

95-100%

No. & % of household

contacts given INH

preventive therapy

(under 5 years of age)

100% No. of under 5 years old

household contacts given

INH preventive therapy /

No of under 5 years old

household contacts

(X100)

1 <50% 50-75% >75-

95%

95-100%

No and % of TB

patients tested for

HIV

Yes No of TB patients tested

for HIV/ total no. of TB

patients (X100)

1 <50% 50-75% >75-

95%

95-100%

% of TB patients

subjected to drug

susceptibility testing

(DST) out of eligible

ones

100% No of TB patients DST

tested /total no. of

eligible TB patients

(X100)

1 <50% 50-75% >75-

95%

95-100%

2/3/2010 21

Indicators Jordan

2007-2008

Score Syria

2007-2008

Score Sudan

2007-2008

Score

Report completeness 100% 4 70% in 2007 2 92.5% in 2007 3.00

Treatment supervision

& support

DOT in place 4 DOT in place 4 DOT is rarely

implemented

1

Adherence to

standardized treatment

regimens

Yes 4 Yes 4 Yes 4

Treatment success rate 71% 2 86% 8 81% 6

%of annual supervisory

visits with feedback

reports out of planned

from central to

intermediate and from

intermediate to

peripheral levels

75-99% 3 75-99% 3 Only 7 states

out of 15 were

subjected to

one supervisory

visit per year

from central

level

2

2/3/2010 22

Indicators Jordan

2007-2008

Score Syria

2007-2008

Score Sudan

2007-2008

Score

% household contact evaluated for

TB (all ages)

96-100% 4 42% 1 NA 0

% household contact evaluated for

TB (under 5 years of age)

NA 0 NA 0 NA 0

No. & % of household contacts given

INH preventive therapy (under 5

years of age)

100% 4 135/396

(34%)

1 Not in place 0

No and % of TB patients tested for

HIV

100% 4 14 1 671 in Q3,

2008, in 8

states out of

15 only

1

% of TB patients DST tested out of

eligible ones

100% 4 100% 4 None 0

% of MDR-TB under treatment 100% 4 23/41 (56%

in 2008)

2 None 0

2/3/2010 23

Summary table on the implementation of the Stop TB

strategy in the different countries

Components

(Domains)

No of

indicators

%

weightMax

score

Jordan Syria

N

Sudan

Score % Score % Score %

ACSM 6 18 24 20 83 13 54 13 54

PPM 6 18 32 29 91 29 91 9 28

Suspect

management 3 9 16 16 100 14 88 0 0

Laboratory

network 7 21 28 21 75 17 61 13 46

Treatment

and quality

of NTP

surveillance 11 33 48 39 81 31 65 17 35

Total 33 100 148 125 84 104 70 52 35

95% CI

(78-

91%)

(61-

79%)

(22-

48%)2/3/2010

24

2/3/2010 25

Correlation between CDR and Summation Score in 9 EMR countries

% summation score

9080706050403020100

CD

R (

%)

110

100

90

80

70

60

50

40

30

20

10

0

Yemen

syria

Pakistan

Oman

N Sudan

Jordan

Iran

Egypt

Afghanis

Rsq = 0.6162

2/3/2010 26

2/3/2010 27

Descriptive Statistics

70.3333 18.5135 9

58.1111 15.6800 9

CDR

SCORE

Mean Std. Deviation N

Correlations

1.000 .731*

. .025

9 9

.731* 1.000

.025 .

9 9

Pearson Correlation

Sig. (2-tailed)

N

Pearson Correlation

Sig. (2-tailed)

N

CDR

SCORE

CDR SCORE

Correlation is significant at the 0.05 level (2-tailed).*.

2/3/2010 28

TB notification rate (per 100 000 population)

0

2

4

6

8

10

12

14

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

New and relapse New smear-positive

Trend in TB notification in Jordan

2/3/2010 29

TB notification rate (per 100 000 population)

0

5

10

15

20

25

30

35

40

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

New and relapse New smear-positive

Trend in TB notification in Syria

2/3/2010 30

TB notification rate (per 100 000 population)

0

10

20

30

40

50

60

70

80

90

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

New and relapse New smear-positive

Trend in TB notification in North Sudan

Interpretation of the model• The national TB control programmes are encouraged to use

this model to evaluate the case finding processes in their countries and identify areas of weaknesses which should be targeted in future interventions.

• The summary table shows that the NTP performance scores in Jordan and Syria were 84% and 70%, respectively. This is consistent with the Case Detection rate these countries that exceeded 70% in 2007 , with the quality of their surveillance system and with the smooth annual decline (almost plateau phase) in their notifications

• Similarly, Sudan NTP reported a percent summation score of 35%, which is also consistent with the low Case detection rate of 31% in 2007, and with the increase in the annual trend of the disease due to inadequate TB control .

2/3/2010 31

Conclusion

• Countries are advised to use this tool to evaluate whether the situation is consistent with the case detection rate estimated for the country.

• For instance, if the evaluation showed that few gaps were identified while the estimated case detection rate is very low, they would conclude that the country case detection rate needs to be revisited. In such situation, it is recommended to approach WHO with the collected evidence to obtain the necessary technical assistance in carrying out one of the WHO recommended methods to estimate TB incidence in order to revisit the case detection rate and TB burden in that country.

2/3/2010 32