As shown in , there was considerable global variation in the listing of Priority Medicines for Mothers and Children on national essential medicines lists. Data for individual country lists can be found in the Supplemental file (Table S1
). The most frequently listed medicine was paracetamol (variable flexible oral dosage form) which was on 94% (84/89) of lists. Sodium chloride, gentamicin, and oral rehydration salts (ORS) were also frequently listed and appeared on 93% (83/89) of lists.
Figure 1 Percent of national Essential Medicines Lists (n=89) listing each Priority Medicine for Mothers and Children.
Six medicines were listed on fewer than 50% of the lists. The least frequently listed medicine was the antimalarial rectal artesunate which was on 8% of lists (7/89); artesunate injection was on 16% (14/89) of lists. Appropriate artemisinin combination therapy, as dispersible tablets or flexible oral solid dosage form, appeared on 36% (32/89) of lists. Procaine benzylpenicillin, for treatment of pediatric pneumonia and neonatal sepsis, was on 50% (45/89) of the lists. Zinc, for treatment of diarrhoea in children, was included on only 15% (13/89) of lists.
For prevention and treatment of postpartum hemorrhage in women, oxytocin was more prevalent on the lists than misoprostol; included on 55 (62%) and 31 (35%) of lists, respectively. Cefixime, for treatment of uncomplicated anogenital gonococcal infection in woman was on 26% (23/89) of lists. Magnesium sulfate injection for treatment of severe pre-eclampsia and eclampsia was on 50% (45/89) of the lists.
Twenty-four of the national essential medicine lists were last updated prior to 2007. There was one list from 1999; all others prior to 2007 were from 2001 to 2007. The four priority medicines most recently added to the WHO Model Essential Medicines List were misoprostol, cefixime, nifedipine, and zinc, all added in 2006. The more up to date lists were more likely to contain the four medicines added in 2006 than the older lists (). One exception is nifedipine which until 2005 had been listed on the WHO Model Essential Medicines List as an antihypertensive.
Listing on national essential medicines lists of four recently added to WHO Model List by date of list.
shows that there is substantial regional variation in the listing of medicines for mothers. Misoprostol was more likely to be listed on country essential medicines lists in the WPRO region than any other region.
Percent of national Essential Medicines Lists listing Priority Medicines for Mothers by WHO Region.
There was even greater global variability in the listing of selected medicines for children (). The African continent has the highest number of malaria cases and deaths, with 174000 cases and 596,000 deaths estimated in 2010. This is followed by Southeast Asia with 28000 cases and 38000 deaths estimated in 2010 
. Thus, listing of the antimalarials is particularly important for the AFRO and SEARO regions. As shown in , AFRO region countries were more likely to list artemisinin combination therapy than artesunate in either formulation, while the countries with EMLs in the SEARO region were more likely to list artemisinin combination and artesunate injection rather than artesunate rectal. The rectal form of artesunate, which is suitable for children, was not widely available in any region.
Percent of national Essential Medicines Lists listing Priority Medicines for Children by WHO Region.
Countries with the highest incidence of malaria cases and deaths also do not uniformly list the artesunate medicines. In 2010, 15 countries (12 of which are in the AFRO region) had more than 10,000 cases of malaria per 100,000 
. Of these 15 countries, 7 had an essential medicines list included in this study: Burundi, Ghana, Maurtania, Senegal, Sudan, Yemen and The Solomon Islands. In the AFRO region, Burundi, Ghana, Mauritania, and Senegal listed artemisinin combination, while only Ghana listed artesunate (both rectal and injection). In the EMRO region, both Sudan and Yemen listed artemisinin combinations, Sudan listed only artesunate rectal, and Yemen listed neither preparation for artesunate. The Solomon Islands, in the WPRO region, listed all 3 antimalarials on its essential medicines list.
Procaine benzylpenicillin for pneumonia, although relatively inexpensive and widely available, was listed on only about 50% of the country lists in each region. Although the WHO recommended formulation of oral rehydration salts was found on over 90% of lists globally, zinc sulfate was listed in only 30% of countries in the AFRO region and less than 10% of countries in the AMRO, EMRO, and WPRO regions.