Monitoring at the Household Level

Methods, Problems, and Use of Critical Information

A Simplified Conceptual Outline: Where does this information fit?

• Provision of services: Adequately iodized salt must be available in the marketplace

• Utilization of services: Consumers must be aware of the importance, and use iodized salt

• Coverage: An adequate proportion of the population must consistently use iodized salt

• Impact: Periodic measurement should show adequate iodine intake as measured by urinary iodine

Salt Production,

Importation, and

Distribution

Is iodized salt available?

Does it meet the iodine needs of the

population?

Does it consistently meet standards?

??

?

Internal and External Monitoring

Provision of services

Salt Production,

Importation, and

Distribution

Insures that salt available to population meets government legal requirements regarding

iodine content

Internal and External Monitoring

Use of Iodized Salt,

Awareness, Cost

And Cultural Habits

Is iodized salt being used?

Does the population

recognize the importance?

??

?

KAP studies, IEC evaluations, price and consumption surveys

Utilization of services

Use of Iodized Salt,

Awareness, Cost

And Cultural Habits

KAP studies, IEC evaluations, price and consumption surveys

Provides an understanding of constraints to use of iodized

salt that may ultimately affect coverage

Household Use

of Iodized

Salt

Do the majority of households

use iodized salt?

Are some groups missed?

??

?

Household coverage surveys, sentinel site coverage assessment

Coverage

Household Use

of Iodized

Salt

Household coverage surveys, sentinel site coverage assessment

Provides a quantitative measure of household use,

and can confirm adequacy of iodine content throughout

distribution

Iodine Status of

The Population

Has iodine deficiency been

eliminated?

Are any groups still deficient?

??

?

Urinary Iodine Assessment in different population

groups

Impact

Iodine Status of

The Population

Urinary Iodine Assessment in different population

groups

Confirms elimination of iodine deficiency at the

population level, or among different high risk target

groups

• Household level monitoring includes understanding purchasing patterns using qualitative techniques, and estimating coverage

• Coverage may be single most important indicator

Assessing Purchasing Habits and Preferences

• KAP surveys, focus group discussions, key informant interviews and other qualitative techniques are used

• Helps with initial program development, in understand key issues influencing decision to use iodized salt, including price, mis-perceptions or concerns about safety and usage, cultural habits

• Usually do not need to assess quantity of salt consumed: varies from 5-15 gms/person/day on average

Assessing Coverage

• Can use sentinel models to assess specific geographic areas

• Ideally population-based, representative sampling at a national level, on a periodic basis

Salt testing in

schools can provide

coverage estimate, while

building awareness • Developed as part of science curriculum•Uses salt test kits to demonstrate presence of iodine•Provides a rough coverage estimate among households with children attending the school

Questions raised :

• Coverage within sentinel sites (schools, clinics)

Is the figure representative of all endemic areas?

Is there bias due to the special attention given sentinel sites??

Population-based Coverage Estimation

• Should be easily included in periodic national surveys (DHS, MICS, Food/Agricultural Surveys, Employment Surveys)

• Can be done using classic immunization (EPI) cluster survey method

Cluster Survey Coverage Protocol

• Developed in response to need for simple immunization coverage figure

• Addresses sampling issues to insure representativeness

• Based on a random selection of households from weighted selection of villages or other administrative units

Survey Coverage Protocol Describes:

• Selection of the geographic area or other administrative unit that the population sampled will represent (usually a district or region)

• Selection of areas or sub-units from which to select households

• Selection of households within sub-units• Collecting data from individuals

Coverage Survey

• Provides a statistically valid estimate of the proportion of households with iodized salt present, and/or stating use of iodized salt

• Provides an opportunity to test salt at the household level in a representative sample of households

• A sample size of 900 is adequate regardless of total population sampled

• Is usually accurate to within + or – 10% of the estimate

Questions raised :

• Coverage surveysIs there bias in household selection?

Is the salt tested the salt usually used?

Does the geographic area sampled adequately reflect the national population?

?

Interpretation of Low Coverage:

Does it reflect poor or inconsistent production level quality assurance?

Does it reflect the specifics of the geographic area selected?

Does it reflect consumer concerns about iodized salt?

?Availability / Supply

Issues

Technical Sampling

Issues

Demand Issues

Actions To Be Taken

Review total tonnage of iodized salt imported: Is it adequate to meet needs?

Increase external monitoring and enforcement (monitoring at import sites)

Investigate coverage further

Review educational activities: Are IEC efforts effective?

Addresses supply issue

Ensures adequate quality entering the

country

Addresses demand issues

Resolves sampling or geographic

representation concerns

Example of Population Proportionate Sampling

sub-unit (village, ward, ..)

Population Cumulative Population

Areas selected

Random start plus sampling

interval

Sampling interval calculations

1 480 480 2 555 1035 1 718 3 657 1692 4 489 2181 1 1976 5 367 2548

Total population=37741 Total number of areas=30 Sampling interval = 1258

(37741/30)

6 456 3004 7 1299 4303 1 3234 8 345 4648 1 4492 9 333 4981 10 777 5758 1 5750

Random start = random number between 1 and 1258 For this example = 718

11 888 6646 12 675 7321 1 7008 13 324 7645 14 865 8510 1 8266 15 567 9077 16 756 9833 1 9524 17 1234 11067 1 10782 18 3465 14532 2 12040

13298 19 567 15099 1 14556 20 878 15977 1 15814 21 898 16875 22 909 17784 1 17072 23 345 18129 24 345 18474 1 18330 25 556 19030 26 675 19705 1 19588 27 564 20269 28 867 21136 1 20846 29 933 22069 30 967 23036 1 22104 31 876 23912 1 23362 32 347 24259 33 879 25138 1 24620 34 1266 26404 1 25878