The Pediatric Heart Network Normal Echocardiogram Database Study had unanticipated challenges. We sought to describe these challenges and lessons learned to improve the design of future studies.

Challenges were divided into three categories: enrolment, echocardiographic imaging, and protocol violations. Memoranda, Core Lab reports, and adjudication logs were reviewed. A centre-level questionnaire provided information regarding local processes for data collection. Descriptive statistics were used, and chi-square tests determined differences in imaging quality.

For the 19 participating centres, challenges with enrolment included variations in Institutional Review Board definitions of “retrospective” eligibility, overestimation of non-White participants, centre categorisation of Hispanic participants that differed from National Institutes of Health definitions, and exclusion of potential participants due to missing demographic data. Institutional Review Board amendments resolved many of these challenges. There was an unanticipated burden imposed on centres due to high numbers of echocardiograms that were reviewed but failed to meet submission criteria. Additionally, image transfer software malfunctions delayed Core Lab image review and feedback. Between the early and late study periods, the proportion of unacceptable echocardiograms submitted to the Core Lab decreased (14 versus 7%, p < 0.01). Most protocol violations were from eligibility violations and inadvertent protected health information disclosure (overall 2.5%). Adjudication committee reviews led to protocol changes.

Numerous challenges encountered during the Normal Echocardiogram Database Study prolonged study enrolment. The retrospective design and flaws in image transfer software were key impediments to study completion and should be considered when designing future studies collecting echocardiographic images as a primary outcome.

We sought to analyse the variation in the incidence of patent ductus arteriosus over three recent time points and characterise ductal ligation practices in preterm infants in the United States, adjusting for demographic and morbidity factors.

Using the Kids’ Inpatient Database from 2003, 2006, and 2009, we identified infants born at ⩽32 weeks of gestation with International Classification of Diseases, Ninth Revision diagnosis of patent ductus arteriosus and ligation code. We examined patient and hospital characteristics and identified patient and hospital variables associated with ligation.

Of 182,610 preterm births, 30,714 discharges included a patent ductus arteriosus diagnosis. The rate of patent ductus arteriosus diagnosis increased from 14% in 2003 to 21% in 2009 (p<0.001). A total of 4181 ligations were performed, with an overall ligation rate of 14%. Ligation rate in infants born at ⩽28 weeks of gestation was 20% overall, increasing from 18% in 2003 to 21% in 2009 (p<0.001). The ligation rate varied by state (4–28%), and ligation was associated with earlier gestational age, associated diagnoses, hospital type, teaching hospital status, and region (p<0.001).

The rates of patent ductus arteriosus diagnosis and ligation have increased in the recent years. Variation exists in the practice of patent ductus arteriosus ligation and is influenced by patient and non-patient factors.

Identify trends of enrolment and key challenges when recruiting infants with complex cardiac diseases into a multi-centre, randomised, placebo-controlled drug trial and assess the impact of efforts to share successful strategies on enrolment of subjects.

Rates of screening, eligibility, consent, and randomisation were determined for three consecutive periods of time. Sites collectively addressed barriers to recruitment and shared successful strategies resulting in the Inventory of Best Recruiting Practices. Study teams detailed institutional practices of recruitment in post-trial surveys that were compared with strategies of enrolment initially proposed in the Inventory.

The number of screened patients increased by 30% between the Initial Period and the Intermediate Period (p = 0.007), whereas eligibility decreased slightly by 7%. Of those eligible for entry into the study, the rate of consent increased by 42% (p = 0.025) and randomisation increased by 71% (p = 0.10). During the Final Period, after launch of a competing trial, fewer patients were screened (−14%, p = 0.06), consented (−19%, p = 0.12), and randomised (−34%, p = 0.012). Practices of recruitment in the post-trial survey closely mirrored those in the Inventory.

Early identification and sharing of best strategies of recruitment among all recruiting sites can be effective in increasing recruitment of critically ill infants with congenital cardiac disease and possibly other populations. Strategies of recruitment should focus on those that build relationships with families and create partnerships with the medical providers who care for them. Competing studies pose challenges for enrolment in trials, but fostering trusting relationships with families can result in successful enrolment into multiple studies.