Changes in the prevalence of breast feeding in preterm infants discharged from neonatal units : a register study over 10 years

Objective: There are indications that the prevalence of exclusively breastfed preterm infants is decreasing in Sweden. The objective was to investigate trends in exclusive breast feeding at discharge from Swedish neonatal units and associated factors in preterm infants. Design, setting and participants: This is a register study with data from the Swedish Neonatal Quality Register. Data from 29 445 preterm infants (gestational age (GA) <37 weeks) who were born during the period 2004–2013 were retrieved. Data included maternal, perinatal and neonatal characteristics. Data were analysed for the whole population as well as for 3 GA groups. Results: From 2004 to 2013, the prevalence of exclusive breast feeding decreased, in extremely preterm (GA 22–27 weeks) from 55% to 16%, in very preterm (GA 28–31 weeks) from 41% to 34% and in moderately preterm infants (GA 32–36 weeks) from 64% to 49%. The decline was statistically significant (p<0.001) in all 3 GA groups. This decline remained significant when adjustments were made for factors negatively associated with exclusive breast feeding and which became more prevalent during the study period, that is, small for GA (all groups) and maternal mental illness (very preterm and moderately preterm infants). Conclusions: In the past 10 years, Sweden has experienced a lower rate of exclusive breast feeding in preterm infants, especially in extremely preterm infants. The factors analysed in this study explain only a small proportion of this decline. The decline in exclusive breast feeding at discharge from neonatal units raises concern and present challenges to the units to support and promote breast feeding.

Methodology used in studies reporting chronic kidney disease prevalence : a systematic literature review

BACKGROUND: Many publications report the prevalence of chronic kidney disease (CKD) in the general population. Comparisons across studies are hampered as CKD prevalence estimations are influenced by study population characteristics and laboratory methods. METHODS: For this systematic review, two researchers independently searched PubMed, MEDLINE and EMBASE to identify all original research articles that were published between 1 January 2003 and 1 November 2014 reporting the prevalence of CKD in the European adult general population. Data on study methodology and reporting of CKD prevalence results were independently extracted by two researchers. RESULTS: We identified 82 eligible publications and included 48 publications of individual studies for the data extraction. There was considerable variation in population sample selection. The majority of studies did not report the sampling frame used, and the response ranged from 10 to 87%. With regard to the assessment of kidney function, 67% used a Jaffe assay, whereas 13% used the enzymatic assay for creatinine determination. Isotope dilution mass spectrometry calibration was used in 29%. The CKD-EPI (52%) and MDRD (75%) equations were most often used to estimate glomerular filtration rate (GFR). CKD was defined as estimated GFR (eGFR) <60 mL/min/1.73 m(2) in 92% of studies. Urinary markers of CKD were assessed in 60% of the studies. CKD prevalence was reported by sex and age strata in 54 and 50% of the studies, respectively. In publications with a primary objective of reporting CKD prevalence, 39% reported a 95% confidence interval. CONCLUSIONS: The findings from this systematic review showed considerable variation in methods for sampling the general population and assessment of kidney function across studies reporting CKD prevalence. These results are utilized to provide recommendations to help optimize both the design and the reporting of future CKD prevalence studies, which will enhance comparability of study results.