Brief report: The KIDSCREEN follow-up study on Health-related Quality of Life (HRQoL) in Spanish children and adolescents. Pilot test and representativeness.

The Spanish KIDSCREEN follow-up study reassessed the Spanish baseline sample (n=840) of the European KIDSCREEN study 3 years later (2006). The aims of this paper were to describe the KIDSCREEN follow-up study and the pilot test, and to analyze participation rates and representativeness. Instruments included the KIDSCREEN-52 HRQoL measure and a set of scales including the possible explanatory variables. Focus groups and individual interviews were carried out in a pilot test. Participants were compared with non-participants at baseline, and also with Eurostat census data. Twenty-two out of 24 subjects were interviewed in the pilot test. Fifteen items needed to be modified after the pilot test. Participation rate reached 54% (n=454). Participants (mean age=12.71 years old) were on average 6 months younger than non-participants (p=0.03), and from more educated families. KIDSCREEN follow-up instrumentation seems adequate for collecting factors with potential influence on HRQoL. Follow-up respondents' representativeness seems to be acceptable.

Lithium carbonate in the treatment of drug-induced leukopenia in patients with solid tumors.

The authors report on the first part of an ongoing controlled trial (52 cases) on the evaluation of the effectiveness of Li2CO3 treatment of drug-induced leukopenia in patients with solid tumors. The results indicate that treatment with 750 mg/day per os of Li2CO3 for 7 days is capable of raising the leukocyte count to a highly significant extent, without serious side effects. The leukocytosis is due to an increase in neutrophil granulocytes.

[The Spanish version of the German health-related quality of life questionnaire for children and adolescents: the Kindl]. / Versión española del cuestionario alemán de calidad de vida relacionada con la salud en población infantil y de adolescentes: el Kindl.

OBJECTIVES: To obtain a Spanish version of the Kindl semantically and culturally equivalent to the original German version and to test its psychometric properties. MATERIAL AND METHODS: The methodology used in the adaptation process was based on the forward-backward translation method. To assess the psychometric properties of the Spanish Kindl, the pilot test of the project "Screening for and promotion of HRQL in children and adolescents: a European Public Health perspective (Kidscreen)" it was include in. A classroom was selected for each educational level (8-16 years old) from three schools in Gerona and Barcelona. The Spanish Kindl was administered twice, one week apart. Internal consistency was assessed by computing Cronbach alpha and test-retest stability was assessed using intraclass correlation coefficients (ICC). Analysis of variance was performed according to age, sex, type of school, and self-perceived health status. RESULTS: Half of the items (12/24) required minor changes during the adaptation process. The response rate was 91 % (n = 447). Internal consistency was acceptable for most domains (alpha range = 0.40-0.88), as was test-retest stability (ICC range = 0.52-0.80). Girls and older teenagers scored worse in most domains (p < 0.01). No differences were found by type of school. CONCLUSIONS: The Spanish version of the Kindl showed adequate reliability and validity coefficients and represents a new HRQL instrument that can be applied in pediatric clinical practice and public health.

Risk genes in head and neck cancer: a systematic review and meta-analysis of last 5 years.

The aim of this work was to identify risk genes related to the development and progression of squamous cell carcinoma head and neck (SCCHN) and do a meta-analysis of available estimates. Eligible gene/polymorphism studies were identified by electronic searches. Individual participant data of 8540 patients with HNC and 9844 controls from 19 genetic studies were analyzed, yielding adjusted (tobacco, gender, age and alcohol) odds ratios (OR) and 95% confidence intervals (CIs) comparing cases with controls. A meta-analysis was done on the studies that applied fixed and random models. People have an increase of polymorphism expression related to inflammation (NFKB1-294-ATTG, TNFα308-A2A2/A2A1, and TNFß252- B2B2/B2B1) or carcinogenic metabolism (GSTM1 null, and CYP1A1 m1/m1), representative of malignancy development. Furthermore, the increased expression of genes associated with the stabilization and repair of the cellular (OGG1-Asp267Asn, Ser279Gly Ile253Phe, 1578A>T, 1582C>T Ala399Glu (1542C>A) 1582insG 1543_1544delCT), and genes associated with the regulation of proliferation, apoptosis or tumor survival (miRNA499-CT/CC, CRYABC802G-CG/GG) are considered as risk factors. In this scheme, only the polymorphisms of ADH7A92G-GG and DEC1606-T/C genes are protective against malignancy transformation. The TP53, GSTM1 and CYPA1genes have been evaluated in more than one study and analyzed for homogeneity in each genotype. The meta-analysis showed no significant association between different allelic variants of Arg72Pro rs1042522 and SCCHN risk. In a model of tumorigenesis, an increased risk of SCCHN is associated with DNA repair and DNA stabilization genes. In addition, the polymorphisms involved in inflammation and carcinogenic metabolism processes represent an increased risk of SCCHN.

Participación en un estudio para valorar la Atención Primaria de Salud entre afiliados de una obra social universitaria / Participation in a study to assess primary health care among members of university health insurance in Argentina / ParticipaþÒo em uma pesquisa para avaliar osciudados primários da saúde entre filiados e filiadasde um plano médico universitário na Argentina

Objetivo: Describir la proporción de localización, participación y respuesta en una encuesta para valorar la atención primaria de la salud de afiliados de una obra social universitaria. Métodos: Estudio piloto descriptivo transversal. Muestreo aleatorio simple de 500 personas adultas de la base de datos de afiliaciones. Se calcularon proporciones de localización, participación, respuesta y respuesta total, luego se analizaron por sexo, edad, tipo de afiliación y modo de administración. Resultados: El 61,8% de afiliados fue localizado, el 84,5% de las personas localizadas aceptó participar y el 64,4% de ellas respondió el cuestionario, alcanzando una proporción de respuesta total del 54,4%. Las personas jóvenes fueron relativamente menos localizadas (52,2%; p<0,01) y la mayor proporción de respuesta total se consiguió en las mayores de 65 años (68,2%; p<0,05). Conclusiones: La localización fue dificultosa pero hubo una buena aceptación del estudio. Los medios informatizados de administración fueron preferidos pero tuvieron una baja respuesta(AU)

Aim: To describe the location, participation and response to a survey to assess primary health care in members of a University Health Insurance.Materials and methods: Pilot cross-sectional descriptive study. Simple random sample of 500 adults from membersÆ database. Proportions of location, participation, response and total response were calculated and analyzed according to sex, age, and type of membership and administration. Results: 61.8% of members were found, 84.5% agreed to participate and 64.4% answered the questionnaire, reaching a total response rate of 54.4%. Young people were less likely to be localized (52.2%, P <0.01) and higher total response rate was achieved in people over 65 (68.2%, P <0.05).Conclusions: Finding the members was difficult but there was a good level of study acceptance. The computerized questionnaire showed strong preference but low response(AU)

Participación en un estudio para valorar la Atención Primaria de Salud entre afiliados de una obra social universitaria / Participation in a study to assess primary health care among members of university health insurance in Argentina / Participação em uma pesquisa para avaliar osciudados primários da saúde entre filiados e filiadasde um plano médico universitário na Argentina

Objetivo: Describir la proporción de localización, participación y respuesta en una encuesta para valorar la atención primaria de la salud de afiliados de una obra social universitaria. Métodos: Estudio piloto descriptivo transversal. Muestreo aleatorio simple de 500 personas adultas de la base de datos de afiliaciones. Se calcularon proporciones de localización, participación, respuesta y respuesta total, luego se analizaron por sexo, edad, tipo de afiliación y modo de administración. Resultados: El 61,8% de afiliados fue localizado, el 84,5% de las personas localizadas aceptó participar y el 64,4% de ellas respondió el cuestionario, alcanzando una proporción de respuesta total del 54,4%. Las personas jóvenes fueron relativamente menos localizadas (52,2%; p<0,01) y la mayor proporción de respuesta total se consiguió en las mayores de 65 años (68,2%; p<0,05). Conclusiones: La localización fue dificultosa pero hubo una buena aceptación del estudio. Los medios informatizados de administración fueron preferidos pero tuvieron una baja respuesta

Aim: To describe the location, participation and response to a survey to assess primary health care in members of a University Health Insurance.Materials and methods: Pilot cross-sectional descriptive study. Simple random sample of 500 adults from members’ database. Proportions of location, participation, response and total response were calculated and analyzed according to sex, age, and type of membership and administration. Results: 61.8% of members were found, 84.5% agreed to participate and 64.4% answered the questionnaire, reaching a total response rate of 54.4%. Young people were less likely to be localized (52.2%, P <0.01) and higher total response rate was achieved in people over 65 (68.2%, P <0.05).Conclusions: Finding the members was difficult but there was a good level of study acceptance. The computerized questionnaire showed strong preference but low response

Changes in health-related quality of life (HRQoL) in a population-based sample of children and adolescents after 3 years of follow-up.

OBJECTIVES: To assess changes in health-related quality of life (HRQoL) in children and adolescents over a 3-year period and to examine factors associated with change. METHODS: A representative sample of Spanish children and adolescents aged 8-18 years and their parents completed the KIDSCREEN-52 questionnaire at baseline and again after 3 years. Data were also collected on gender, pubertal development (PD), and family socio-economic status (SES). Change in HRQOL over time was evaluated using effect sizes (ES). Generalized estimating equations (GEE) were used to analyze associations among changes in KIDSCREEN scores, socio-demographic factors, and pubertal development. RESULTS: Response rate at follow-up was 54% (n = 454). Overall, HRQoL worsened in eight out of the ten KIDSCREEN dimensions, with ES ranging from -0.10 (Moods and Emotions) to -0.34 (Psychological Well-being). The decrease was most marked in the intermediate age group (13-17 years of age at follow-up) and in girls. In the GEE models, pubertal development more strongly impacted changes in girls than in boys. CONCLUSIONS: In this representative, population-based sample of children and adolescents, moderate decrements in HRQoL were observed after 3 years. Changes were particularly important among girls and in relation to pubertal development. These results could provide useful reference data for other longitudinal studies in population sub-groups.

[The renal biopsy in the post-genomic era.]. / L'approccio alla biopsia renale e le nuove possibilita' diagnostiche: cosa cambia nell'era postgenomica.

Histological and immunohistological examination of renal biopsy material is the method of choice for the diagnosis of glomerular and interstitial renal disease. However, our understanding of renal damage is still largely incomplete because of the limited knowledge of the etiology and pathogenesis of numerous kidney diseases. For this reason, we still provide unspecific treatment to kidney patients, which is generally aimed at counteracting inflammatory alterations and slowing progression towards renal failure, without intervening directly in the cause of the disease. The recent development of the ''omics'' (genomics, proteomics, metabolomics) following the enormous progress of high-throughput technologies and information technology tools is profoundly transforming our knowledge in every biomedical field, including nephrology. It is expected that in a very short time a better understanding of both physiological and pathological events in the kidney will translate into different therapeutic strategies, possibly targeted to individual needs. Nephrologists and renal pathologists must take these changes into account and realize that a new approach to renal biopsy is urgently required. Renal biopsy material has in fact an enormous importance in the generation of new knowledge and in the validation of experimental results from high-throughput technologies and animal models. Furthermore, it is conceivable that a new classification of renal diseases will be needed soon as a result of the improved knowledge. For these reasons, renal biopsy material should be adequately processed and preserved according to modern methods, and collaborative projects should be fostered to achieve standardized methods and avoid a waste of energy in singular efforts.

[Spanish adaptation of the disease-specific questionnaire MSQOL-54 in multiple sclerosis patients]. / Adaptación al español del cuestionario específico MSQOL-54 para pacientes con esclerosis múltiple.

INTRODUCTION: The Multiple Sclerosis Quality of Life 54 (MSQOL-54) is a health-related quality of life specific questionnaire for multiple sclerosis (MS) patients. The objective of this study was to develop the Spanish version of the MSQOL-54 and to obtain a conceptually equivalent version to the original one for its use in patients with MS in the first phase of the project. METHODS: A transcultural adaptation procedure was designed according to the following phases: a) two independent translations made by bilingual native Spanish speaking translators (forward translation); b) a revision of the items by an expert panel; c) a back translation by a bilingual native English speaking person; d) comparison with the original version (expert panel and advise by the original authors), and e) cognitive debriefing (interviews with subjects with MS) to test the comprehension and feasibility of the instrument. RESULTS: Ten interviews were carried out with 5 men and 5 women with MS, aged 21 to 54 years, with different education levels and EDSS scores ranging from 1,0 to 8,0. Most of the patients found the questionnaire easy to fill out and the understanding favorable. Only one item (item 51) was modified after the cognitive debriefing to improve its comprehension. Finally, a final pretest version was obtained. CONCLUSIONS: The procedure carried out maximizes the conceptual equivalence between the original MSQOL-54 and the translated version and shows that the Spanish pre-test version is comprehensible and its administration feasible in patients with MS. The psychometric properties must be evaluated in the next phase of the project.

[Reliability and validity of the Spanish version of the health and quality-of-life questionnaire, the Vecú et Santé Perçue de l'Adolescent (VSP-A)]. / Fiabilidad y validez del cuestionario de salud y calidad de vida para adolescentes Vecú et Santé Perçue de l'Adolescent (VSP-A).

OBJECTIVE: To assess the psychometric properties of the Spanish version of the Vecú et Santé Perçue de l'Adolescent (VSP-A) in terms of reliability and validity. DESIGN: Cross-sectional study. SETTING: Pilot study parallel to the European Kidscreen project. Two secondary schools, one public and one private, were selected for their suitability in Barcelona and Gerona (Catalonia, Spain). The sample unit was the classroom. PARTICIPANTS: A sample of 354 adolescents aged 12 to 18 years old was selected. MAIN MEASUREMENTS: The Spanish VSP-A questionnaire was administered, and again a week later to check its test-retest stability. The KINDL questionnaire was administered in parallel. RESULTS: The response rate was 82% (n=291). The Spanish version of the VSP-A showed good internal consistency and acceptable test-retest reliability (Cronbach's alpha: 0.69-0.92, intraclass correlation coefficient [ICC]: 0.69-0.74) in most domains. Domains measuring a similar concept in the VSP-A and KINDL had closer correlation coefficients than those measuring different constructs (P<.05), which demonstrates its convergent validity. Girls had worse self-perceived health than boys (lower vitality, physical and emotional well-being and self-esteem, and a lower general score on the VSP-A; p<.01). These differences were more obvious in older teens (16-18 years old). CONCLUSIONS: The Spanish VSP-A showed good psychometric properties and results were consistent with the original French version. The results mean we have an adequate HRQL instrument for teens and for use in primary care and public health.

Prevalencia de asma y su impacto en la calidad de vida de los adolescentes escolarizados de la ciudad / Asthma prevalence and its impact on the quality of life of school adolescents in the city

Antecedentes. La presencia de asma o su combinación con otros factores afectaría la calidad de vida de los adolescentes. No habría estudios que contemplen estas asociaciones en la ciudad. Objetivo. Describir la frecuencia de asma, factores asociados y su impacto en la calidad de vida relacionada con la salud (CVRS) en adolescentes de 13 a 18 años de la ciudad. Material y métodos. Encuesta a adolescentes de escuelas públicas y privadas durante el año 2008, que empleó un muestreo por conglomerados en 2 etapas y un cuestionario autoadministrado. La prevalencia de asma se midió con la metodología ISAAC, y la CVRS por medio de la versión argentina KIDSCREEN-52. Se analizaron los factores asociados a asma por medio de la prueba del χ2 y regresión logística múltiple. Se estratificó el análisis de la CVRS en presencia y ausencia de asma, controlando por género y presencia de adicciones. Resultados. Se encuestó a 2.566 adolescentes. La prevalencia de asma fue 15% (379/2.566): 9% (221/2.566) con síntomas indicadores de asma (SIA) y 6% (158/2.566) con asma declarada. El 10% presentó condiciones con elevada sospecha de asma. Las puntuaciones medias en asmáticos fueron más bajas que en los no asmáticos en todas las dimensiones de la CVRS, aunque las diferencias no fueron significativas. Los adolescentes con asma y adicciones presentaron las puntuaciones más bajas, particularmente en la percepción sobre bienestar físico y el estado de ánimo. Asma se relacionó con baja percepción del estado de ánimo, aún controlando por otras variables. Conclusiones. La prevalencia de asma en adolescentes de la ciudad puede considerarse como intermedia a nivel global, regional y nacional, aunque existiría una proporción elevada de casos con subdiagnóstico. El asma se relacionó con una baja percepción del estado de ánimo.(AU)

Background. The presence of asthma or its combination with other factors, affect the quality of life of adolescents. There wouldn´t be studies that consider these associations in the city. Objective. To describe the prevalence of asthma, associated factors and their impact on quality of life related to health (HRQOL) in adolescents 13 to 18 years in the city. Methods. A survey of adolescents in public and private schools in 2008 that used a cluster sampling in two stages and a self-administered questionnaire. The prevalence of asthma was measured using the ISAAC methodology and HRQL by Argentina's version KIDSCREEN-52. The factors associated with asthma were analyzed by the χ2 test and multiple logistic regression. Stratified analysis of HRQOL in the presence and absence of asthma, controlling for gender and presence of addictions. Results. 2.566 adolescents were surveyed. Prevalence of asthma: 15% (379/2.566) - 9% (221/2.566) with SIA and 6% (158/2.566) with asthma declared. 10% had conditions with high suspicion of asthma. The mean scores were lower in asthmatics than in non-asthmatics in all dimensions of HRQOL, although the differences were not significant. Adolescents with asthma and addictions had the lowest scores, particularly in the perception of physical and mood. Asthma was associated with low perception of mood, even when controlling for other variables. Conclusions. The prevalence of asthma in adolescents in the city can be regarded as intermediate global, regional and national levels, although there would be a high proportion of cases with subdiagnosis. Asthma was associated with a low perception of mood.(AU)

Allele frequencies of polymorphisms of TNFA, IL-6, IL-10 and IFNG in an Italian Caucasian population.

Polymorphisms in the regulatory and intronic regions of several cytokines have been associated with differential cytokine production. In this paper we genotyped, using the polymerase chain reaction-sequence-specific primers (PCR-SSP) method, a series of 363 healthy Italian Caucasians with the aim of obtaining a reference population for further studies on the role of cytokines in the inflammatory and immune responses. We also compared the results to those for other populations. The polymorphisms analysed were those of tumour necrosis factor alpha (TNFA), interleukin 6 (IL-6), interleukin 10 (IL-10) and interferon gamma (IFNG). We found that the frequency of allele TNFA*1 at position -380 was 87.7% and that of TNFA*2 was 12.4%, significantly different from those of the UK and Japanese populations but not different from that of a population in Gambia. For IL-10 the frequencies of alleles -1082A and -1082G were 63.0% and 37.0% and those of alleles -819C, - 819T, -592C and -592A were 70.8, 29.2, 70.8 and 29.2%, respectively, significantly different from those observed in south-east England, in Manchester and in an Oriental population from southern China. The frequencies of IL-6 alleles - 174C and -174G were 29.0 and 71.0%, respectively; for IFNG polymorphisms at position -874, in the population under evaluation, the alleles -874T and -874A were present in 44.7 and 55.3% of the subjects, respectively. Genotype frequencies of IL-6 were significantly different from those observed in populations from Germany and from the UK. The analysis carried out by our group indicates that there is heterogeneity in the frequencies of the cytokine polymorphisms among the different Caucasian populations, and this underlines the importance of a 'local' reference population when evaluating the clinical relevance of cytokine gene polymorphisms.

[Growth of breastfed and bottle-fed infants up to 2 years of age: CLACYD (Lactation, Alimentation, Growth and Development) study 1993-1995]. / Crecimiento de niños amamantados y alimentados con biberón hasta los 2 años de vida: estudio CLACYD, 1993-1995.

Studies done in various countries show important differences in the growth of breastfed and bottle-fed children. In addition, it has been found that breast-fed children grow more slowly beginning at the age of 2 or 3 months in comparison with the reference pattern of the U.S. National Center for Health Statistics (NCHS) and the World Health Organization (WHO). These results cast doubt on whether maximum growth is the same as optimal growth. The objective of this study was to compare the growth in weight and length, from birth to 24 months, for a group of children who were breast-fed with that of a group who were bottle-fed. The study was also intended to describe the growth of the breastfed group in relation to the NCHS/WHO norms and a WHO "12-month breast-fed pooled data set." For this research, data were analyzed from the "Cordoba: lactation, feeding, growth, and development" study (or CLACYD study, for its Spanish-language acronym). That study looked at a representative cohort, stratified by social class, of children born in 1993 in the city of Cordoba, Argentina. The researchers analyzed anthropometric data on 74 children who were breast-fed during the first year of life and on 108 bottle-fed children. The data had been recorded, using standardized techniques, at birth and at 6, 12, and 24 months of age. Both groups were homogenous with respect to the age and schooling of the parents, social stratum, birth order, maternal height, and child's weight and length at birth. The living conditions (housing construction and availability of water and sewer services) were better among the group that was bottle-fed (P = 0.04). The breast-fed children had a lower weight and a shorter length at 6, 12, and 24 months than did the bottle-fed children. The breast-fed children also showed a slowing in growth with respect to the NCHS/WHO guidelines beginning in the second semester. This indicates that the NCHS/WHO norms are not totally adequate for evaluating the growth of breast-fed children in Cordoba, Argentina. In the high and middle social strata, the values for the breast-fed group resembled those for the WHO "pooled data set," both in weight and length. In the low and very low social strata, weight values were satisfactory, but the figures for length were less than those of the "pooled data set." The gap in length found among the low and very low social strata does not reduce the validity of the WHO "pooled data set" reference, but rather indicates the influence of living conditions on linear growth.

Correlates of breastfeeding duration in an urban cohort from Argentina.

AIM: To analyse factors associated with the duration of breastfeeding in a representative cohort of mothers and children, including socio-demographic and cultural characteristics, breastfeeding antecedents, perinatal factors and perinatal healthcare practices. METHODS: The study was conducted in the city of Cordoba, between 1993 and 1998. Mother-child binomials from all public and private hospitals were asked to participate. Follow-up consisted of home visits at 30 d, 6, 12, 24, 36, 48 and 50 mo. Information was obtained on 650 healthy newborns. Cessation of breastfeeding during the first 24 mo of life was analysed using the Kaplan-Meier method, and factors associated with weaning were studied using Cox's proportional risk regression. RESULTS: The median duration of breastfeeding was 4 mo. Factors associated with weaning were: the introduction of artificial formulas within 30 d postpartum [relative risk (RR) = 2.27; 95% confidence interval (CI) = 1.82-2.82]; breastfeeding of a previous child for less than 6 mo (RR = 1.64; 95% CI = 1.32-2.02); delay in the first mother-child contact for over 90 min (RR = 1.50; 95% CI = 1.17-1.93); mother's having completed primary or partially completed secondary education (RR = 1.40; 95% CI = 1.01-1.92) or completed secondary education or higher (RR = 1.59; 95% CI = 1.14-2.22); primiparous mother (RR = 1.39; 95% CI = 1.12-1.74) and; the mother recalling having been breastfed for less than 6 mo (RR = 1.27; 95% CI = 1.01-1.61). CONCLUSIONS: The purpose of strategies to promote breastfeeding should be to eliminate inappropriate care practices, such as delay in the first mother-child contact, as well as reducing the impact of other factors leading to the introduction of artificial milk. Moreover, mothers need more and better support from professionals and peers.

Premature cessation of breastfeeding in infants: development and evaluation of a predictive model in two Argentinian cohorts: the CLACYD study, 1993-1999. Córdoba Lactation, Feeding, Growth and Development study.

UNLABELLED: The objective of this study was to develop a model to predict premature cessation of breastfeeding of newborns, in order to detect at-risk groups that would benefit from special assistance programmes. The model was constructed using 700 children with a birthweight of 2000 g or more, in 2 representative cohorts in 1993 and 1995 (CLACYD I sample) in Córdoba, Argentina. Data were analysed from 632 of the cases. Mothers were selected during hospital admittance for childbirth and interviewed in their homes at 1 mo and 6 mo. To evaluate the model, an additional sample with similar characteristics was drawn during 1998 (CLACYD II sample). A questionnaire was administered to 347 mothers during the first 24-48 h after birth and a follow-up was completed at 6 mo, with weaning information on 291 cases. Premature cessation of breastfeeding was considered when it occurred prior to 6 mo. A logistic regression model was fitted to predict premature end of breastfeeding, and was applied to the CLACYD II sample. The calibration (Hosmer-Lemeshow C statistic) and the discrimination [area under the receiver operating characteristics (ROC) curve] of the model were evaluated. The predictive factors of premature end of breastfeeding were: mother breastfed for less than 6 mo [odds ratio (OR) = 1.84, 95% confidence interval (CI) 1.26-2.70], breastfeeding of previous child for less than 6 mo (OR = 4.01, 95% CI 2.58-6.20), the condition of the firstborn child (OR = 2.75, 95% CI 1.79-4.21), the first mother-child contact occurring after 90 min of life (OR = 1.88; 95% CI 1.22-2.91) and having an unplanned pregnancy (OR = 1.50, 95% CI 1.05-2.15). The calibration of the model was acceptable in the CLACYD I sample (p = 0.54), as well as in the CLACYD II sample (p = 0.18). The areas under the ROC curve were 0.72 and 0.68, respectively. CONCLUSION: A model has been suggested that provides some insight onto background factors for the premature end of breastfeeding. Although some limitations prevent its general use at a population level, it may be a useful tool in the identification of women with a high probability of early weaning.