Symptom development in originally asymptomatic CPAM diagnosed prenatally: a systematic review

Utility of Postnatal Chest X-Ray in Newborns for the Evaluation of Prenatally Suspected Congenital Pulmonary Airway Malformation: A Single-Center Experience

OBJECTIVE

 The aim of the study is to assess the necessity of chest X-ray (CXR) during the newborn hospitalization for all patients with prenatally suspected congenital pulmonary airway malformation (CPAM).

STUDY DESIGN

 This is a retrospective chart review of all infants delivered with prenatally suspected CPAM at our high-risk delivery hospital from January 2013 through April 2020 (n = 44). Nonparametric tests assessed the association between postnatal CXR findings, prescribed follow-up timeline, and neonatal outcomes.

RESULTS

 Mean follow-up period recommended was 6.4 weeks regardless of CXR findings in the neonatal period (p = 0.81). Additionally, patients who required respiratory support at or after birth were not more likely to have a lesion identified on chest X-ray (odds ratio [OR] = 0.72, 95% confidence interval [CI], 0.18-2.64, p = 0.71).

CONCLUSION

 Neonatal hospital course and future follow-up plan of patients with prenatally suspected CPAM were not altered by information from the CXR obtained in the immediate neonatal period, suggesting that this CXR may not be necessary in the asymptomatic patient.

KEY POINTS

· Immediate postnatal X-ray of prenatally diagnosed CPAM does not alter planned follow-up interval.. · Immediate postnatal X-ray does not alter surgical plan for CPAM.. · Postnatal X-ray is not absolutely required for asymptomatic newborns with CPAM..

[Congenital pulmonary malformations : Diagnosis and treatment]

PERFORMANCE

Congenital pulmonary malformations (CPM) are rare and can be associated with high morbidity. Clinical presentation, diagnostic procedures, imaging, and therapy of CPM are discussed.

ACHIEVEMENTS

Today, most CPM can be diagnosed prenatally by ultrasound. Postnatally, respiratory symptoms up to respiratory failure and recurrent lower respiratory tract infection are typical findings. Due to low diagnostic accuracy of chest x‑ray in CPM, all children with prenatal diagnosis of CPM or postnatally suspected CPM should undergo cross-sectional imaging.

PRACTICAL RECOMMENDATIONS

Based on imaging alone, the various subtypes of CPM cannot be definitively differentiated, which is why histological confirmation remains the gold standard. Surgical resection is the standard of care with minimally invasive procedures increasingly being employed. In certain situations, a watch-and-wait approach is possible.

No Pathogenic DICER1 Gene Variants in a Cohort Study of 28 Children With Congenital Pulmonary Airway Malformation

BACKGROUND

Distinguishing congenital pulmonary airway malformations (CPAMs) from pleuropulmonary blastoma (PPB) can be challenging. Previously diagnosed patients with CPAM may have been misdiagnosed and we may have missed DICER1-associated PPBs, a diagnosis with important clinical implications for patients and their families. To gain insight in potential misdiagnoses, we systematically assessed somatic DICER1 gene mutation status in an unselected, retrospective cohort of patients with a CPAM diagnosis.

METHODS

In the Amsterdam University Medical Center (the Netherlands), it has been standard policy to resect CPAM lesions. We included all consecutive cases of children (age 0-18 years) with a diagnosis of CPAM between 2007 and 2017 at this center. Clinical and radiographic features were reviewed, and DICER1 gene sequencing was performed on DNA retrieved from CPAM tissue samples.

RESULTS

Twenty-eight patients with a surgically removed CPAM were included. CPAM type 1 and type 2 were the most common subtypes (n = 12 and n = 13). For 21 patients a chest CT scan was available for reassessment by two pediatric radiologists. In 9 patients (9/21, 43%) the CPAM subtype scored by the radiologists did not correspond with the subtype given at pathology assessment. No pathogenic mutations and no copy number variations of the DICER1 gene were found in the DNA extracted from CPAM tissue (0/28).

CONCLUSIONS

Our findings suggest that the initial CPAM diagnoses were correct. These findings should be validated through larger studies to draw conclusions regarding whether systematic DICER1 genetic testing is required in children with a pathological confirmed diagnosis of CPAM or not.

LEVEL OF EVIDENCE

Level IV.

[Right upper lobe pulmonary sequestration as a rare cause of recurrent spontaneous pneumothorax]

A 19-year-old patient after previous wedge resection of the right upper pulmonary lobe a year ago urgently admitted with recurrent right-sided spontaneous pneumothorax. According to standard management of spontaneous pneumothorax, we performed diagnostic thoracoscopy and drainage of the right pleural cavity with regular X-ray examinations. However, these measures were ineffective. The patient was scheduled for surgery, and we intraoperatively observed an unusual cause of pneumothorax. Thus, we present spontaneous pneumothorax following right upper lobe pulmonary sequestration. The uniqueness of this case is associated with unusual manifestation and non-standard localization of rare lesion. A few cases of pneumothorax in similar patients are described in the world literature. The key limiting factor in diagnosis of such defects (identification of aberrant vessel supplying abnormal lung parenchyma) is the lack of routine CT angiography in patients diagnosed with pneumothorax. That is why CT changes were interpreted as postoperative ones, and the true cause was established only during redo surgery. A thorough inspection of the pleural cavity and alertness regarding unusual appearance of the right upper pulmonary lobe made it possible to suggest a non-standard diagnosis, avoid complications (bleeding from afferent vessel) and perform adequate lung resection.

Selection of potential targets for stratifying congenital pulmonary airway malformation patients with molecular imaging: is MUC1 the one?

Currently there is a global lack of consensus about the best treatment for asymptomatic congenital pulmonary airway malformation (CPAM) patients. The somatic KRAS mutations commonly found in adult lung cancer combined with mucinous proliferations are sometimes found in CPAM. For this risk of developing malignancy, 70% of paediatric surgeons perform a resection for asymptomatic CPAM. In order to stratify these patients into high- and low-risk groups for developing malignancy, a minimally invasive diagnostic method is needed, for example targeted molecular imaging. A prerequisite for this technique is a cell membrane bound target. The aim of this study was to review the literature to identify potential targets for molecular imaging in CPAM patients and perform a first step to validate these findings.A systematic search was conducted to identify possible targets in CPAM and adenocarcinoma in situ (AIS) patients. The most interesting targets were evaluated with immunofluorescent staining in adjacent lung tissue, KRAS+ CPAM tissue and KRAS- CPAM tissue.In 185 included studies, 143 possible targets were described, of which 20 targets were upregulated and membrane-bound. Six of them were also upregulated in lung AIS tissue (CEACAM5, E-cadherin, EGFR, ERBB2, ITGA2 and MUC1) and as such of possible interest. Validating studies showed that MUC1 is a potential interesting target.This study provides an extensive overview of all known potential targets in CPAM that might identify those patients at risk for malignancy and conducted the first step towards validation, identifying MUC1 as the most promising target.

Pediatric thoracoscopic lung resections: a comprehensive analysis of congenital lesion cases

BACKGROUND

Congenital lung lesions in pediatric patients may be managed conservatively or by video assisted thoracoscopic surgery (VATS). This study aimed to determine the complications after VATS for congenital lung lesions in children.

METHODS

All children undergoing a lung resection between January 2009 and June 2022 were retrospectively identified. Children undergoing a primary open lobectomy or a resection other than a congenital lung lesion were excluded. Both early (<30 days) and late postoperative pulmonary complications were determined. The primary endpoint was postoperative complications within 30 days.

RESULTS

In total, 56 patients were included, with a median age of 13 months (IQR 9-37). A VATS lobectomy were performed in 46 patients (82%), an extralobar sequestration in 8 patients (14%), an wedge resection in 1 patient and a segment resection in 1 patient. During the COVID pandemic, fewer resections were performed with an increase in symptomatic patients. A conversion to open occurred in 6 patients (11%), of which a preoperative lung infection was associated with an increased risk thereof(p = 0.004). The median follow-up was 22 months (IQR 7-57) and all patients were alive. A postoperative complication (Clavien Dindo ≥3) occurred in 9 patients and complications without the need of intervention in 6 patients. During follow-up a pneumonia occurred in 11 patients.

CONCLUSION

There seems to be a shift towards delayed surgery with an increase in symptomatic congenital lung malformations, which might lead to an increase in postoperative complications.

Long-term neurodevelopment in children with resected congenital lung abnormalities

To determine whether children who underwent resection of a congenital lung abnormality (CLA) are at higher risk for neurodevelopmental impairments than peers in the general population. The study population consisted of children born between 1999-2018 who underwent resection of a symptomatic CLA. Neurocognitive development (intelligence, memory, attention, visuospatial processing, executive functioning) and motor function of this population are monitored through our structured, prospective longitudinal follow-up program at the ages of 30 months, 5, 8, and 12 years. We compared study population scores with Dutch norm values using one-sample t-tests and one-sample binominal proportion tests. Forty-seven children were analyzed. The 8-year-olds showed significant impairments in sustained attention through the Dot Cancellation Test (mean z-scores -2.4; [-4.1; -0.8], p = 0.006 and -7.1; [-12.8; -1.4], p = 0.02 for execution speed and fluctuations respectively). Visuospatial memory was impaired at 8 years, though only in 1 out of 3 assessment tools (Rey Complex Figure Test z-scores (-1.0; [-1.5; -0.5], p < 0.001). Further neurocognitive outcomes were unimpaired at all tested ages. Regarding motor function outcomes, mean z-scores of total motor functioning were unimpaired across assessed ages. However, at 8 years, significantly more children than expected had definite motor problems (18% vs 5%, 95% CI [0.052; 0.403], p = 0.022).   Conclusion: This evaluation reveals impairment in some subtests of sustained attention, visuospatial memory and motor development. However, globally, normal neurodevelopmental outcomes were found throughout childhood. We recommend testing for neurodevelopmental impairments in children who underwent surgery for CLA only if associated morbidities are present or if caregivers express doubts about their daily functioning. What is Known: • In general, surgically managed CLA cases seldom suffer from long-term surgery-related morbidity and show favorable lung function. What is New: • Long-term neurocognitive and motor function outcome appear unimpaired within surgically managed CLA cases. We recommend testing for neurodevelopmental impairments in children who underwent surgery for CLA only if associated morbidities are present or if caregivers express doubts about their daily functioning.

COllaborative Neonatal Network for the first European CPAM Trial (CONNECT): a study protocol for a randomised controlled trial

INTRODUCTION

Consensus is lacking on the optimal management of asymptomatic congenital pulmonary airway malformation (CPAM). For future studies, the CONNECT consortium (the COllaborative Neonatal Network for the first European CPAM Trial)-an international collaboration of specialised caregivers-has established consensus on a core outcome set of outcome parameters concerning respiratory insufficiency, surgical complications, mass effect and multifocal disease. These outcome parameters have been incorporated in the CONNECT trial, a randomised controlled trial which, in order to develop evidence-based practice, aims to compare conservative and surgical management of patients with an asymptomatic CPAM.

METHODS AND ANALYSIS

Children are eligible for inclusion after the CPAM diagnosis has been confirmed on postnatal chest CT scan and they remain asymptomatic. On inclusion, children are randomised to receive either conservative or surgical management. Subsequently, children in both groups are enrolled into a standardised, 5-year follow-up programme with three visits, including a repeat chest CT scan at 2.5 years and a standardised exercise tolerance test at 5 years.The primary outcome is exercise tolerance at age 5 years, measured according to the Bruce treadmill protocol. Secondary outcome measures are molecular genetic diagnostics, validated questionnaires-on parental anxiety, quality of life and healthcare consumption-, repeated imaging and pulmonary morbidity during follow-up, as well as surgical complications and histopathology. This trial aims to end the continuous debate surrounding the optimal management of asymptomatic CPAM.

ETHICS AND DISSEMINATION

This study is being conducted in accordance with the Declaration of Helsinki. The Medical Ethics Review Board of Erasmus University Medical Centre Rotterdam, The Netherlands, has approved this protocol (MEC-2022-0441). Results will be disseminated through peer-reviewed scientific journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05701514.

Congenital Cystic Adenomatoid Malformations of the lung, a retrospective study of diagnosis, treatment strategy and postoperative morbidity in surgically-treated patients

OBJECTIVES

The purpose of this study was to evaluate diagnosis, clinical signs and strategy in Congenital Cystic Adenomatoid Malformations (CCAM).

METHODS

In this retrospective study, patients with thoracic surgery for CCAM lesions at the University Hospitals of Leuven from July 1993 to July 2016 were searched. Data on diagnosis, prenatal ultrasound findings, clinical signs, lesion site, CCAM type, associated anomalies, imaging, surgical approach and postoperative morbidity were reviewed. The Fisher's exact and Mann-Whitney tests were used as appropriate.

RESULTS

A total of 55 patients were identified with CCAM. In 65% (n = 36/55), CCAM was detected on prenatal ultrasound. Prenatal symptoms due to hydrops or mass-effect were present in 22% (n = 8/36), of which eventually 6 had need for prenatal intervention (Thoracoamniotic shunting or Intrauterine Puncture). Surgery was performed elective in 40% patients (n = 22/55), while others developed clinical signs with need for semi-urgent surgery, with clinical signs of pulmonary infection and respiratory distress being the most common. Most patients had a single lobectomy via mini-thoracotomy. Postoperative complications and length of stay were observed to be significantly higher in CCAM with preoperative clinical signs.

CONCLUSIONS

Surgery in asymptomatic CCAM patients can be performed safely with few postoperative complications and can be planned at young age in patients with high risk of developing clinical signs later in life.

The Management of Asymptomatic Congenital Pulmonary Airway Malformation: Results of a European Delphi Survey

Consensus on the optimal management of asymptomatic congenital pulmonary airway malformation (CPAM) is lacking, and comparison between studies remains difficult due to a large variety in outcome measures. We aimed to define a core outcome set (COS) for pediatric patients with an asymptomatic CPAM. An online, three-round Delphi survey was conducted in two stakeholder groups of specialized caregivers (surgeons and non-surgeons) in various European centers. Proposed outcome parameters were scored according to level of importance, and the final COS was established through consensus. A total of 55 participants (33 surgeons, 22 non-surgeons) from 28 centers in 13 European countries completed the three rounds and rated 43 outcome parameters. The final COS comprises seven outcome parameters: respiratory insufficiency, surgical complications, mass effect/mediastinal shift (at three time-points) and multifocal disease (at two time-points). The seven outcome parameters included in the final COS reflect the diversity in priorities among this large group of European participants. However, we recommend the incorporation of these outcome parameters in the design of future studies, as they describe measurable and validated outcomes as well as the accepted age at measurement.

Thoracoscopic segmentectomy for a large previously undiagnosed CPAM presenting as a spontaneous pneumothorax: A case report

Introduction

Incidentally found congenital pulmonary airway malformations (CPAM) in older children are extremely rare and have traditionally been managed with minimally invasive versus open lobectomy of the affected lobe.

Presentation of case

In this report, we present a 11-year-old male who presented with a recurrent spontaneous pneumothorax and was found to have a large symptomatic CPAM confined to a single segment of the right lower lobe. The patient was successfully treated with thoracoscopic segmentectomy without any residual disease seen on follow up imaging.

Discussion

Minimally invasive thoracoscopic approach has many advantages over open approach including better pain control, reduced hospital length of stay, and decreased intraoperative blood loss. With increasing use of minimally invasive approaches, lung-sparing surgery has demonstrated to be a viable and an attractive option for definitive resection of CPAM, without compromising resection margins and/or future lung function.

Conclusion

This report demonstrates that minimally invasive lung-sparing surgical treatment of a large CPAM is feasible in older children.

•

Older children with CPAM can present with a spontaneous pneumothorax.

•

CPAM confined to a segment of a single lobe should be managed with segmentectomy.

•

VATS segmentectomy for CPAM in older children can be successful.

An Incidental Finding of Congenital Pulmonary Airway Malformation Type 3 During a Forensic Autopsy for a Sudden Infant Death: A Case Report With a Brief Literature Review

ABSTRACT

Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic airway malformation, is a developmental disorder of the lower respiratory tract. It is subdivided into 5 types based on clinical and pathologic features. Type 3, an adenomatoid type of CPAM, is the second rarest form of CPAM, occurring in approximately 5% of all CPAM cases. This article reports an autopsy of a nearly 11-week-old male infant, found unresponsive in bed with his mother. She had fallen asleep after breastfeeding a few hours prior. Although the autopsy and additional technical examinations did not uncover the exact cause of death, CPAM type 3 was eventually identified on histological examination. Taking into account the context of this case, in which accidental asphyxia/neglect could not be ruled out, it is thought that the presence of CPAM might have contributed to the demise of the infant. As CPAM is a rare congenital disorder, the diagnosis could easily be missed. Therefore, this article aims to raise awareness of this diagnosis and points out the clinical and pathologic features of this disorder.

DICER1 Syndrome and Cancer Predisposition: From a Rare Pediatric Tumor to Lifetime Risk

DICER1 syndrome is a rare genetic condition predisposing to hereditary cancer and caused by variants in the DICER1 gene. The risk to present a neoplasm before the age of 10 years is 5.3 and 31.5% before the age of 60. DICER1 variants have been associated with a syndrome involving familial pleuropulmonary blastoma (PPB), a rare malignant tumor of the lung, which occurs primarily in children under the age of 6 years and represents the most common life-threatening manifestation of DICER1 syndrome. Type I, II, III, and Ir (type I regressed) PPB are reported with a 5-year overall survival ranging from 53 to 100% (for type Ir). DICER1 gene should be screened in all patients with PPB and considered in other tumors mainly in thyroid neoplasms (multinodular goiter, thyroid cancer, adenomas), ovarian tumors (Sertoli-Leydig cell tumor, sarcoma, and gynandroblastoma), and cystic nephroma. A prompt identification of this syndrome is necessary to plan a correct follow-up and screening during lifetime.

Creating enriched training sets of eligible studies for large systematic reviews: the utility of PubMed's Best Match algorithm

INTRODUCTION

Solutions like crowd screening and machine learning can assist systematic reviewers with heavy screening burdens but require training sets containing a mix of eligible and ineligible studies. This study explores using PubMed's Best Match algorithm to create small training sets containing at least five relevant studies.

METHODS

Six systematic reviews were examined retrospectively. MEDLINE searches were converted and run in PubMed. The ranking of included studies was studied under both Best Match and Most Recent sort conditions.

RESULTS

Retrieval sizes for the systematic reviews ranged from 151 to 5,406 records and the numbers of relevant records ranged from 8 to 763. The median ranking of relevant records was higher in Best Match for all six reviews, when compared with Most Recent sort. Best Match placed a total of thirty relevant records in the first fifty, at least one for each systematic review. Most Recent sorting placed only ten relevant records in the first fifty. Best Match sorting outperformed Most Recent in all cases and placed five or more relevant records in the first fifty in three of six cases.

DISCUSSION

Using a predetermined set size such as fifty may not provide enough true positives for an effective systematic review training set. However, screening PubMed records ranked by Best Match and continuing until the desired number of true positives are identified is efficient and effective.

CONCLUSIONS

The Best Match sort in PubMed improves the ranking and increases the proportion of relevant records in the first fifty records relative to sorting by recency.

Establishment of a multidisciplinary fetal center streamlines approach for congenital lung malformations

PURPOSE

Fetuses with a diagnosis of congenital lung malformations (CLM) on prenatal imaging are commonly referred to a multi-disciplinary specialty team for prenatal assessment and postnatal management. The net effect of such services is broadly stated to improve the outcomes of affected newborns. However, these claims are relatively unsubstantiated.

METHODS

After IRB approval, a retrospective review of children diagnosed with CLM from 2008 to 2018 and referred to a large urban children's hospital was performed. A comparison was performed between prenatally diagnosed patients having a multi-disciplinary fetal center evaluation (FC) and prenatally diagnosed patients who did not receive a referral or were seen prior to the establishment of the center (NON-FC).

RESULTS

Eighty-eight live-born patients with a prenatal diagnosis of CLM were identified, with 49 in the FC group and 39 NON-FC. Thirty-four (63%) and 23 (59%) patients underwent operative resection of CLM, respectively. FC patients presented earlier at first postnatal follow-up (42 vs. 145 days, p = .03), had fewer preoperative office visits (2.1 vs. 3.4, p = .0003), received fewer preoperative chest radiographs (0.5 vs. 1.3; p = .002) and chest computed tomography (0.9 vs. 1.4; p = .001), and had fewer preoperative pneumonias (0 vs. 17.4%; p = .02) compared to their NON-FC counterparts. FC patients were also more likely to undergo resection at an earlier age (217 vs. 481 days, p = .003) and were more likely to undergo a minimally invasive resection (75% vs. 39.1%, p = .015). There were no differences in post-operative outcomes between the two groups.

CONCLUSION

Children with a prenatal diagnosis of CLM appear to benefit from an organized multi-specialty team approach in several impactful parameters. Hospital systems and providers that invest in similar strategies are likely to achieve improved outcomes in the care of newborns prenatally diagnosed with a CLM.

Impact of Additional Anomalies on Postnatal Outcomes in Congenital Lung Malformations

BACKGROUND

Approximately 20% of fetuses diagnosed with congenital lung malformations (CLMs) are found to have additional anomalies. We aim to determine if additional anomalies have an impact on postnatal outcomes for patients with CLMs.

METHODS

After institutional review board approval, we performed a retrospective review of live-born patients with CLMs from 2008 to 2018. All patients were prenatally diagnosed with CLMs. Clinical information pertaining to additional congenital anomalies and outcomes was collected from the electronic health record and analyzed.

RESULTS

Of the 88 patients who had a prenatal diagnosis of CLMs, 20.5% had additional anomalies. Ten of the 18 patients (56%) were considered to have a major anomaly in addition to CLMs. Outcomes for patients electing nonoperative management of CLMs were similar between those with and without an additional anomaly. Although patients with an additional anomaly were more likely to have perinatal respiratory complications (44% versus 17%, P = 0.03), the number of preoperative clinic and emergency department visits, age at surgery, minimally invasive approach to surgical resection of CLM, estimated blood loss, length of hospital stay, intubation, duration of intubation, 30-day postoperative complications, and long term sequelae were not statistically different. This held true when stratified for major versus minor anomalies.

CONCLUSIONS

Twenty percent of fetuses diagnosed with CLM in our population have additional anomalies. Newborns with additional anomalies have a higher risk of pre-excision pulmonary complications. However, the overall outcomes of all patients with CLMs are similar.

Congenital lung lesions

Diagnosis and management of congenital lung malformations has evolved dramatically over the past several decades. Advancement in imaging technology has enabled earlier, more definitive diagnoses and, consequently, more timely intervention in utero or after birth, when indicated. These advancements have increased overall survival rates to around 95% from historical rates of 60%. However, further refinement of diagnostic technique and standardization of treatment is needed, particularly as the increased sensitivity of diagnostic imaging results in more frequent diagnoses. In this article, we provide an updated review of the diagnostic strategies, management, and prognosis of congenital lung malformations.

Esophageal duplication cyst presenting with stridor in a child with congenital pulmonary airway malformation: A case report and literature review

RATIONALE

Esophageal duplication cyst (EDC) is a rare developmental aberration originated from the embryonic foregut. It may remain asymptomatic but produce local mass effect on surrounding organs if rapid enlarges. EDC may sometimes accompany with other congenital malformations. Congenital pulmonary airway malformation (CPAM) is a congenital lung malformation with an unknown chance of developing symptoms. Here we report a rare case of esophageal duplication cyst with type 2 congenital pulmonary airway malformation (CPAM).

PATIENT CONCERNS

A 16-month old boy with a prenatal diagnosis of type 2 CPAM presented progressive stridor and respiratory distress and was admitted to our hospital under the diagnosis of pneumonia. The patient responded poorly to antibiotics. A chest Xray (CXR) showed consolidation over the left upper lobe with trachea deviated to right side. A chest computed tomography (CT) revealed a cystic lesion sized 3.3 × 3.3 cm in the superior mediastinum.

DIAGNOSES

Post-operative pathological report confirmed the diagnosis of esophageal duplication cyst.

INTERVENTIONS

We pre-medicated the patient with steroids and inhaled bronchodilators for airway maintenance. Then the patient received tumor resection via median sternotomy.

OUTCOMES

The patient recovered without complication and discharged smoothly 4 days after the surgery.

LESSONS

EDC is a rare but potentially life-threatening disease owning to compression of large airways. Chest CT scan could detect the lesion non-invasively and should be considered in patients with persistent stridor, as well as CXR findings of the trachea deviated by a mass lesion in mediastinum, especially for those with CPAM.

Crowdsourcing the Citation Screening Process for Systematic Reviews: Validation Study

BACKGROUND

Systematic reviews (SRs) are often cited as the highest level of evidence available as they involve the identification and synthesis of published studies on a topic. Unfortunately, it is increasingly challenging for small teams to complete SR procedures in a reasonable time period, given the exponential rise in the volume of primary literature. Crowdsourcing has been postulated as a potential solution.

OBJECTIVE

The feasibility objective of this study was to determine whether a crowd would be willing to perform and complete abstract and full text screening. The validation objective was to assess the quality of the crowd's work, including retention of eligible citations (sensitivity) and work performed for the investigative team, defined as the percentage of citations excluded by the crowd.

METHODS

We performed a prospective study evaluating crowdsourcing essential components of an SR, including abstract screening, document retrieval, and full text assessment. Using CrowdScreenSR citation screening software, 2323 articles from 6 SRs were available to an online crowd. Citations excluded by less than or equal to 75% of the crowd were moved forward for full text assessment. For the validation component, performance of the crowd was compared with citation review through the accepted, gold standard, trained expert approach.

RESULTS

Of 312 potential crowd members, 117 (37.5%) commenced abstract screening and 71 (22.8%) completed the minimum requirement of 50 citation assessments. The majority of participants were undergraduate or medical students (192/312, 61.5%). The crowd screened 16,988 abstracts (median: 8 per citation; interquartile range [IQR] 7-8), and all citations achieved the minimum of 4 assessments after a median of 42 days (IQR 26-67). Crowd members retrieved 83.5% (774/927) of the articles that progressed to the full text phase. A total of 7604 full text assessments were completed (median: 7 per citation; IQR 3-11). Citations from all but 1 review achieved the minimum of 4 assessments after a median of 36 days (IQR 24-70), with 1 review remaining incomplete after 3 months. When complete crowd member agreement at both levels was required for exclusion, sensitivity was 100% (95% CI 97.9-100) and work performed was calculated at 68.3% (95% CI 66.4-70.1). Using the predefined alternative 75% exclusion threshold, sensitivity remained 100% and work performed increased to 72.9% (95% CI 71.0-74.6; P<.001). Finally, when a simple majority threshold was considered, sensitivity decreased marginally to 98.9% (95% CI 96.0-99.7; P=.25) and work performed increased substantially to 80.4% (95% CI 78.7-82.0; P<.001).

CONCLUSIONS

Crowdsourcing of citation screening for SRs is feasible and has reasonable sensitivity and specificity. By expediting the screening process, crowdsourcing could permit the investigative team to focus on more complex SR tasks. Future directions should focus on developing a user-friendly online platform that allows research teams to crowdsource their reviews.