Respondent-driven sampling: Advantages and disadvantages from a sampling method. / Respondent-driven sampling: ventajas e inconvenientes de un método de muestreo.

This article summarizes the main elements, advantages, and disadvantages of Respondent-driven Sampling (RDS). Some criticisms regarding the feasibility of the inherent assumptions, their point estimators, and the obtained variances are pointed out. This article also comments on the problems observed in the quality of reports. Surveys using RDS should be methodologically sound as they are being applied to define priorities in health programs and develop national and international policies for financing service delivery, among other uses. However, there is considerable potential for bias related to implementation and analytical errors. There is limited empirical evidence on how representative the results obtained by RDS are, and the quest to improve the methodology is still in progress. Nevertheless, to have confidence in RDS results, we must verify that the social structure of the networks conforms to the assumptions required by the theory, that the sampling assumptions are reasonably fulfilled, and that the quality of the report is optimal, particularly for methodological and analytical items.

Este artículo resume algunas consideraciones, ventajas e inconvenientes de esta técnica de muestreo conocida como Respondent-driven Sampling (RDS). Se señalan algunas críticas que han aparecido en la literatura científica respecto a la viabilidad de los supuestos inherentes a esta técnica y, en consecuencia, respecto a los estimadores puntuales y de las varianzas así obtenidas. También, se comentan los problemas observados en la literatura acerca de la calidad de los reportes de este tipo de estudios. Las encuestas que utilizan RDS deben ser metodológicamente de buena calidad, pues están siendo aplicadas extensamente para definir prioridades de programas sanitarios, para desarrollar políticas nacionales e internacionales de financiamiento de prestación de servicios, entre otras aplicaciones. Sin embargo, existe un amplio potencial de sesgo al usar este método, muchos de los cuales están relacionados con la implementación y los errores analíticos. La evidencia empírica sobre cuán representativos son los resultados obtenidos mediante RDS es limitada, y la búsqueda para mejorar la metodología es un área de investigación aún en progreso. No obstante, para tener confianza en los resultados publicados debe verificarse que la estructura social de las redes estudiadas se ajusta a los supuestos requeridos por la teoría de RDS, que los supuestos del muestreo se cumplen razonablemente y que la calidad del reporte es óptima, en particular respecto a los ítems metodológicos y analíticos.

Childbirth experiences of immigrant women in Chile: Trading human rights and autonomy for dignity and good care.

BACKGROUND: Childbirth is a transcendent life experience but may also be a moment of great vulnerability, especially when it occurs outside the mother's country of origin. OBJECTIVE: To explore the perceptions and experiences of Spanish-speaking immigrant women regarding the healthcare they received during labour and childbirth in Santiago, Chile. METHODS: This qualitative, transcendental phenomenological research was performed at two maternity hospitals using purposive criterion sampling. Eighteen individual and two group interviews were conducted. The resulting information was transcribed and then coded and categorised using phenomenological analysis. RESULTS: Six categories were extracted from the narratives which reflect a pragmatic relationship with the healthcare team that included a perception of 'justified' lack of care. The mothers' exercise of autonomy was subjugated by power-knowledge relations between the women and caregiver that compelled them to refrain from expressing their needs and preferences out of fear of abuse. The women valued emotional support, pain relief and satisfaction of needs in association with medical procedures and companionship. The women rated their experiences as positive if they avoided mistreatment and, as 'the essence of the experience', perceived the care as a favour rather than a right. CONCLUSION: Most immigrant women felt that they had received treatment similar to that of native-born mothers. However, low expectations of autonomy shaped their evaluations of the experiences. Also, a high value on companionship and pain relief, characterised the women's experiences of childbirth. These findings of the interviews reflect a need for a stronger focus on empowerment with an emphasis on gender and rights.