2008-12-31-世界卫生组织-2009_STEPS_Country_Report_Malawi_131页_1mb

报告摘要

Malawi National STEPS Survey for Chronic Non-Communicable Diseases and their Risk Factors

Core Content

The Malawi National STEPS Survey was a population-based cross-sectional study conducted in 2009 to assess the prevalence of chronic non-communicable diseases (NCDs) and their risk factors. The survey was a collaborative effort between the Ministry of Health (MoH) and the World Health Organization (WHO), and it aimed to provide evidence-based data for informing public health policies and resource allocation in Malawi.

Main Objectives

To determine the magnitude of NCDs and their risk factors in Malawi.
To assess lifestyle factors and anthropometric measurements that may impact diabetes and cardiovascular risk.
To identify the prevalence and determinants of hypertension, diabetes, and raised cholesterol levels.

Key Findings

A total of 5,206 participants were enrolled, with 67.5% being female.
The overall response rate was 95.5%.
32.9% of participants had raised blood pressure or were on medication for it.
- 37.2% of males vs 29.2% of females had high blood pressure (p < 0.05).
- 94.9% of those with high BP were not on medication or unaware of their condition.
5.6% of participants had diabetes, with no significant difference between males and females (6.5% vs 4.7%).
8.7% of adults aged 25-64 had raised cholesterol levels.
- 11.0% of females vs 6.3% of males had raised cholesterol (p < 0.05).
Risk factors were:
- Tobacco smoking: 14.1% overall (25.9% males vs 2.9% females).
- Alcohol consumption: 16.9% overall (30.1% males vs 4.2% females).
- Physical inactivity: 9.5% overall (12.6% females vs 6.3% males).
- Overweight: 21.9% overall (28.1% females vs 16.1% males).
16.5% of participants had three or more NCD risk factors.

Survey Methodology

A multi-stage cluster sampling design was used to ensure a national representative sample.
The survey was conducted in three stages:
1. Stage 1: Selection of 144 enumeration areas (EAs) using Probability Proportional to Size (PPS) sampling.
2. Stage 2: 40 households were selected from each EA using systematic sampling.
3. Stage 3: One eligible participant (aged 25-64) per household was selected using the Kish Method.
Data was collected using personal digital assistants (PDAs) and included:
- Step 1: Socio-demographic and behavioral data (e.g., tobacco use, alcohol consumption, physical activity, diet).
- Step 2: Physical measurements (e.g., height, weight, blood pressure, waist and hip circumference).
- Step 3: Biochemical tests (e.g., total cholesterol, fasting blood glucose).
Data was weighted for age, gender, and population size and analyzed using WHO STEPS Survey software.

Sample Size Calculation

Initial sample size calculated using the formula:
$$
N = \frac{Z^2 P(1 - P)}{e^2}
$$
With $Z = 1.96$, $P = 0.50$, and $e = 0.05$, the initial estimate was 384 participants.
Adjusted for design effect (1.5) and age-sex estimates (8), the required sample size was 4,608.
Further adjusted for a 20% non-response rate, the final sample size was 5,760.

Survey Implementation

National Team: Composed of representatives from MoH, WHO, and other relevant departments, responsible for protocol development, tool adaptation, stakeholder engagement, and training.
Field Teams: Seven teams of 10 members each, including supervisors, enumerators, health workers, and support staff.
Training: A 3-day workshop was conducted for interviewers and supervisors, covering data collection, ethics, PDA use, and quality control.
Data Collection Tools: Questionnaires, PDAs, and field kits were used. Questionnaires were translated into Chichewa and Tumbuka.
Ethical Clearance: Granted by the Malawi National Research & Ethics Committee.
Survey Period: Conducted from July to September 2009 over a 30-day period.

Significance of the Survey

NCDs, once considered "diseases of the west", are now major public health concerns in developing countries, including Malawi.
The survey highlighted the lack of awareness and treatment among people with hypertension.
It emphasized the need for multi-sectoral action plans and NCD control programs to address the growing burden of NCDs.
The data provides a baseline for future health planning and policy development in Malawi.

Risk Factor Comparison with Other Sub-Saharan Countries

Tobacco smoking: 14.1% in Malawi vs 18.9% in Mauritius, 12.8% in Algeria, etc.
Alcohol consumption: 16.9% in Malawi vs 77.2% in Mozambique, 27.4% in Botswana, etc.
Obesity: 21.9% in Malawi vs 7.1% in Mozambique, 15.7% in Botswana, etc.
Raised blood pressure: 32.9% in Malawi vs 22.4% in Mauritius, 33.1% in Mozambique, etc.
Elevated blood sugar: 4.9% in Malawi vs 14% in Botswana, 10% in Zimbabwe, etc.