[1] Univ Manchester, Div Nursing Midwifery & Social Work, Jean McFarlane Bldg,Oxford Rd, Manchester M13 9PL, England
[2] Keele Univ, Sch Nursing & Midwifery, Keele, England
[3] Univ Hosp North Midlands NHS Trust, Ctr NMAHP Res & Educ Excellence CeNREE, Stoke On Trent, England
[4] Univ Chile, Dept Promoc Salud Mujer & Recien Nacido, Santiago, Chile