World Health Organization 24 Series 10 Guidelines 8 Education 7 Health Services Research 7 Health Surveys 7 Child 5 Delivery of health care 5 Institutional Management Teams 5 Managed Care Programs 5 Staff Development 5 Analgesics, opioid 4 Developing countries 4 Drug and narcotic control 4 Pain classification 4 Pain drug therapy 4 Pain measurement 4 Palliative care 4 Public Health 4 adverse effects 4 Drugs, essential 3 Periodicals 3 Primary health care 3 Public health 3 Research 3 Risk assessment 3 Asia Pacific Observatory on Health Systems and policies 2 Centers for Disease Control and Prevention (U.S.) 2 Chronic Disease - prevention and control 2 Developing Countries 2