Preventive Medicine in Humanitarian Emergencies

4.2. Emergency Needs Assessment

A needs assessment looks at what a community lacks as well as what resources and capacities it can use to address problems. The objective of a needs assessment is to identify gaps between current community needs and resources.

Emergency needs assessments (also called rapid needs assessments) are focused on those needs that can ameliorate the greatest amount of morbidity in the community (Box 8).

Security, transportation, and communication are also key elements of an emergency community needs assessment; however, these components may fall outside the traditional healthcare realm. They will be covered in greater detail under “Conditions of other community resources” at the end of this section.

Water

Water is critical to survival and must always be a top priority. The quantity of water is a higher priority than quality in the immediate post-disaster scenario. Providing clean water will do more to prevent the spread of disease than any other preventive medicine intervention. An estimates of water quantity needs only for drinking varies from 3 to 4 liters/person/day. However, the water needs will increase to 15 to 20 liters/person/day when cooking, cleaning, laundry, and personal hygiene are taken into account. The immediate identification of water sources, ways to protect these resources and methods to improve water quality are top priorities. Water purification systems may eventually be provided by relief agencies. If there are immediate concerns about the safety of the water, then it can be chlorinated by adding 2 drops of bleach (sodium hypochlorite solution) per liter of water.

Nutritional status

Nutritional assessments take into account community needs as well as local resources. Again data, not speculation, is needed. The recommendation for caloric needs in a displaced population is 2,100 Kcal/person per day. Other elements of the nutritional needs assessment include food availability, nutrition quality including availability of adequate micro-nutrients, food security, distribution throughout the community, and cultural factors that affect nutrition.

Common sampling techniques for surveying children’s nutritional status (or other health condition) include random selection (simple or systematic) or cluster sampling. Simple random selection can be done if all the children can be identified, such as by immunization records or a camp census. They are assigned a number and then a random number table is used to select those who will be evaluated for nutritional status.

Systematic random sampling is done by checking every nth household to get enough children for a representative sample. This is useful if the households are reasonably neatly ordered, such as ordered in rows of tents. The interval between each household that is sampled (n) is determined by the total number of households in the community divided by the number of households you wish to sample. For example, to check the nutritional status of children in 450 households out of a total of 2,800 households, you would check every sixth household (2,800 divided by 450). The first household to be sampled would be determined by randomly selecting a number between I and 6. Survey teams would then check the nutritional status of children in every sixth household, beginning with the randomly selected one.

Cluster sampling is a statistical sampling technique that is used for large numbers of people and is beyond the scope of this discussion. A public health professional with training in epidemiology or a standard text on this subject could be used to design a survey using cluster technique.

If random selection (simple or systematic) is used, a sample size of about 450 children is needed. If cluster sampling is used, the sample size should be of about 900 children for an accurate population estimate. If the community size is small enough, it is more accurate to simply check all the children who are in the sentinel population age range.

It is important to bear in mind that the sample size will depend not only on the population size but also on the frequency of the phenomenon being investigated; i.e., the prevalence of this phenomenon in the community.

Shelter

For shelter, the WHO recommends 3.5 to 4 squared meters (m2) per person as the absolute minimal amount of floor space for a displaced population. A rapid assessment of available remaining space will identify any disparity between needs and capacity. Predisaster planning should emphasize the use of community spaces such as schools, churches, and assembly halls for emergency shelter.

Basic sanitation

Basic sanitation is aimed at preventing spread of communicable diseases from indiscriminant defecation. Feces are a concentrated source of human pathogens and can lead to explosive outbreaks of diarrheal diseases. In a post-disaster scenario, effective control of human waste is a top priority. One person can contaminate water used by thousands, and flies can spread fecal material to food supplies, rapidly creating hundreds or thousands of cases of food and waterborne illness.

Local environmental conditions

Conditions that affect community health, such as smoke, chemical spills, floods, landslides, collapsed buildings, terrain slopes, drainages, and insect vectors, are all important to assess during disaster situations.

Health needs

The emergency assessment of health needs is focused on mortality rates and the chief causes of morbidity. Death is the most severe negative health outcome and it must be tracked carefully to understand what is happening in a community. To provide the most accurate information, mortality data should be reported by age, sex, and cause of death.

This data is captured by using patient logbooks or records that record age, sex and chief diagnosis of the patient. This data can be rapidly analyzed to gain an understanding of the chief health threats to the community and used to plan the use of resources accordingly.