Tag: statistics

Cochrane Database Syst Rev. 2021 Mar 16;3:CD013639. doi: 10.1002/14651858.CD013639.pub4.

ABSTRACT

BACKGROUND: The respiratory illness caused by SARS-CoV-2 infection continues to present diagnostic challenges. Our 2020 edition of this review showed thoracic (chest) imaging to be sensitive and moderately specific in the diagnosis of coronavirus disease 2019 (COVID-19). In this update, we include new relevant studies, and have removed studies with case-control designs, and those not intended to be diagnostic test accuracy studies.

OBJECTIVES: To evaluate the diagnostic accuracy of thoracic imaging (computed tomography (CT), X-ray and ultrasound) in people with suspected COVID-19.

SEARCH METHODS: We searched the COVID-19 Living Evidence Database from the University of Bern, the Cochrane COVID-19 Study Register, The Stephen B. Thacker CDC Library, and repositories of COVID-19 publications through to 30 September 2020. We did not apply any language restrictions.

SELECTION CRITERIA: We included studies of all designs, except for case-control, that recruited participants of any age group suspected to have COVID-19 and that reported estimates of test accuracy or provided data from which we could compute estimates.

DATA COLLECTION AND ANALYSIS: The review authors independently and in duplicate screened articles, extracted data and assessed risk of bias and applicability concerns using the QUADAS-2 domain-list. We presented the results of estimated sensitivity and specificity using paired forest plots, and we summarised pooled estimates in tables. We used a bivariate meta-analysis model where appropriate. We presented the uncertainty of accuracy estimates using 95% confidence intervals (CIs).

MAIN RESULTS: We included 51 studies with 19,775 participants suspected of having COVID-19, of whom 10,155 (51%) had a final diagnosis of COVID-19. Forty-seven studies evaluated one imaging modality each, and four studies evaluated two imaging modalities each. All studies used RT-PCR as the reference standard for the diagnosis of COVID-19, with 47 studies using only RT-PCR and four studies using a combination of RT-PCR and other criteria (such as clinical signs, imaging tests, positive contacts, and follow-up phone calls) as the reference standard. Studies were conducted in Europe (33), Asia (13), North America (3) and South America (2); including only adults (26), all ages (21), children only (1), adults over 70 years (1), and unclear (2); in inpatients (2), outpatients (32), and setting unclear (17). Risk of bias was high or unclear in thirty-two (63%) studies with respect to participant selection, 40 (78%) studies with respect to reference standard, 30 (59%) studies with respect to index test, and 24 (47%) studies with respect to participant flow. For chest CT (41 studies, 16,133 participants, 8110 (50%) cases), the sensitivity ranged from 56.3% to 100%, and specificity ranged from 25.4% to 97.4%. The pooled sensitivity of chest CT was 87.9% (95% CI 84.6 to 90.6) and the pooled specificity was 80.0% (95% CI 74.9 to 84.3). There was no statistical evidence indicating that reference standard conduct and definition for index test positivity were sources of heterogeneity for CT studies. Nine chest CT studies (2807 participants, 1139 (41%) cases) used the COVID-19 Reporting and Data System (CO-RADS) scoring system, which has five thresholds to define index test positivity. At a CO-RADS threshold of 5 (7 studies), the sensitivity ranged from 41.5% to 77.9% and the pooled sensitivity was 67.0% (95% CI 56.4 to 76.2); the specificity ranged from 83.5% to 96.2%; and the pooled specificity was 91.3% (95% CI 87.6 to 94.0). At a CO-RADS threshold of 4 (7 studies), the sensitivity ranged from 56.3% to 92.9% and the pooled sensitivity was 83.5% (95% CI 74.4 to 89.7); the specificity ranged from 77.2% to 90.4% and the pooled specificity was 83.6% (95% CI 80.5 to 86.4). For chest X-ray (9 studies, 3694 participants, 2111 (57%) cases) the sensitivity ranged from 51.9% to 94.4% and specificity ranged from 40.4% to 88.9%. The pooled sensitivity of chest X-ray was 80.6% (95% CI 69.1 to 88.6) and the pooled specificity was 71.5% (95% CI 59.8 to 80.8). For ultrasound of the lungs (5 studies, 446 participants, 211 (47%) cases) the sensitivity ranged from 68.2% to 96.8% and specificity ranged from 21.3% to 78.9%. The pooled sensitivity of ultrasound was 86.4% (95% CI 72.7 to 93.9) and the pooled specificity was 54.6% (95% CI 35.3 to 72.6). Based on an indirect comparison using all included studies, chest CT had a higher specificity than ultrasound. For indirect comparisons of chest CT and chest X-ray, or chest X-ray and ultrasound, the data did not show differences in specificity or sensitivity.

AUTHORS’ CONCLUSIONS: Our findings indicate that chest CT is sensitive and moderately specific for the diagnosis of COVID-19. Chest X-ray is moderately sensitive and moderately specific for the diagnosis of COVID-19. Ultrasound is sensitive but not specific for the diagnosis of COVID-19. Thus, chest CT and ultrasound may have more utility for excluding COVID-19 than for differentiating SARS-CoV-2 infection from other causes of respiratory illness. Future diagnostic accuracy studies should pre-define positive imaging findings, include direct comparisons of the various modalities of interest in the same participant population, and implement improved reporting practices.

PMID:33724443 | DOI:10.1002/14651858.CD013639.pub4

J Small Anim Pract. 2021 Mar 15. doi: 10.1111/jsap.13320. Online ahead of print.

ABSTRACT

OBJECTIVES: To determine the association between signalment, selected haematologic and biochemical parameters and referral centre in pet rabbits with imaging evidence of urolithiasis presented to two veterinary teaching hospitals in North America.

MATERIALS AND METHODS: The medical record database of two veterinary teaching hospitals was searched from 2009 to 2019 for records of pet rabbits that received both imaging studies and plasma biochemistry profiles. Information regarding signalment, bodyweight, packed cell volume, total solids, and plasma biochemistry profiles was obtained. Univariable and multivariable logistic regression models were performed to identify statistically significant parameters associated with imaging evidence of urolithiasis.

RESULTS: Of the 324 examined rabbits, 33 (10.2%) had confirmed evidence of urolithiasis on imaging. Increasing plasma calcium and sodium concentrations and referral centre were significantly associated with the presence of urolithiasis on the univariable logistic regression model. However, only plasma calcium concentration and the referral centre demonstrated significant associations on the multivariable logistic regression model.

CLINICAL SIGNIFICANCE: Results indicate that urolithiasis in pet rabbits that receive imaging is associated with mildly increasing plasma calcium concentration and referral centre. The association with referral centre may indicate there are geographic influences on urolithiasis or on imaging. However, the identified associations have low predictive value for the diagnosis of urolithiasis, indicating the need for additional diagnostic modalities.

PMID:33724471 | DOI:10.1111/jsap.13320

J Med Virol. 2021 Mar 16. doi: 10.1002/jmv.26942. Online ahead of print.

ABSTRACT

Few studies exist on the clinical manifestation of COVID-19 in patients who previously had a common cold due to an endemic coronavirus (eCoV). In a retrospective scan of the data obtained in our microbiology laboratory, 64 patients who were diagnosed with an eCoV infection between 2016 and 2020 were identified. National COVID-19 surveillance data showed that four (6.2%) of 64 patients were infected with SARS-CoV-2 by the end of 2020 while, simultaneously, the COVID-19 prevalence in the city of Malatya ranged from 7.8% (PCR-based diagnosis) to 9.2% (total diagnosis). The differences were found statistically significant (6.2 vs 7.8%, p<0.01; 6.2 vs 9.2%, p<0.001). Patient interviews and evaluation of medical records revealed that these four patients did not manifest any severe COVID-19 symptoms despite their substantial co-morbidities, and they did not require hospitalization. Consequently, despite a low number of samples, we determined a lower frequency of COVID-19 among the patients who had a prior eCoV infection, and the results of this study support the previous findings that people with a prior eCoV infection develop a milder case of COVID-19. Our results may provide some insights for future studies aiming at vaccine development, but detailed investigations are still required. This article is protected by copyright. All rights reserved.

PMID:33724483 | DOI:10.1002/jmv.26942

Nat Commun. 2021 Mar 15;12(1):1672. doi: 10.1038/s41467-021-21819-8.

ABSTRACT

X-ray free-electron lasers (XFELs) enable obtaining novel insights in structural biology. The recently available MHz repetition rate XFELs allow full data sets to be collected in shorter time and can also decrease sample consumption. However, the microsecond spacing of MHz XFEL pulses raises new challenges, including possible sample damage induced by shock waves that are launched by preceding pulses in the sample-carrying jet. We explored this matter with an X-ray-pump/X-ray-probe experiment employing haemoglobin microcrystals transported via a liquid jet into the XFEL beam. Diffraction data were collected using a shock-wave-free single-pulse scheme as well as the dual-pulse pump-probe scheme. The latter, relative to the former, reveals significant degradation of crystal hit rate, diffraction resolution and data quality. Crystal structures extracted from the two data sets also differ. Since our pump-probe attributes were chosen to emulate EuXFEL operation at its 4.5 MHz maximum pulse rate, this prompts concern about such data collection.

PMID:33723266 | DOI:10.1038/s41467-021-21819-8

J Minim Access Surg. 2021 Apr-Jun;17(2):159-164. doi: 10.4103/jmas.JMAS_108_19.

ABSTRACT

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (RYGB) has been proven to induce significant weight loss and remission of related co-morbidities in patients with morbid obesity. The long-term follow-up data show weight regain or failure to achieve complete remission of type 2 diabetes mellitus (T2DM) in some patients. In this study, we report weight loss patterns and remission of T2DM in patients with morbid obesity during a 5-year follow-up after RYGB.

OBJECTIVE: The objective was to evaluate outcomes during the follow-up on excess weight loss (EWL) and remission of T2DM after laparoscopic RYGB among Indian patients.

SETTING: The study was conducted in a tertiary care hospital, Kerala, India.

MATERIALS AND METHODS: This is a retrospective study in patients who underwent surgery between 2007 and 2010. The patient demographics, pre- and post-operative body mass index (BMI), co-morbidities and EWL were recorded from the medical records. These data were compared between pre-operative and follow-up intervals till 5 years using statistical approaches.

RESULTS: The study included 157 patients (91 males and 66 females) having a mean pre-operative BMI of 47.91 ± 7.01 kg/m². A significant reduction in the BMI was observed at each follow-up point (P < 0.01) till 5 years after the surgery. The mean percentage of EWL increased from 34.57% ± 12.62% to 71.50% ± 15.41% from 3 months to 5 years after the surgery. Twelve per cent (n = 19) of patients achieved normal BMI (<25 mg/kg²) by 3^rd year after the surgery. However, the remission of T2DM was achieved in >50% of patients within a year of surgery. During the 5^th year, weight regain (1-22 kg) was observed in 36.70% (n = 58) patients, and recurrence of T2DM was observed in two patients.

CONCLUSIONS: The long-term durability of RYGB in the study population was satisfactory with significant weight loss and remission of T2DM.

PMID:33723179 | DOI:10.4103/jmas.JMAS_108_19

J Minim Access Surg. 2021 Apr-Jun;17(2):165-174. doi: 10.4103/jmas.JMAS_154_19.

ABSTRACT

BACKGROUND: Although surgical resection is the main treatment for rectal cancer, the optimal surgical protocol for elderly patients with rectal cancer remains controversial. This study evaluated the feasibility of robot-assisted surgery in elderly patients with rectal cancer.

PATIENTS AND METHODS: This retrospective study enrolled 156 patients aged 28-93 years diagnosed with Stage I-III rectal cancer, who underwent robot-assisted surgery between May 2013 and December 2018 at a single institution.

RESULTS: In total, 156 patients with rectal cancer, including 126 non-elderly (aged < 70 years) and 30 elderly (aged ≥70 years) patients, who underwent robot-assisted surgery were recruited. Between the patient groups, the post-operative length of hospital stay did not differ statistically significantly (P = 0.084). The incidence of overall post-operative complications was statistically significantly lower in the elderly group (P = 0.002). The disease-free and overall survival did not differ statistically significantly between the two groups (P = 0.719 and 0.390, respectively).

CONCLUSIONS: Robot-assisted surgery for rectal cancer was well tolerated by elderly patients, with similar results to the non-elderly patients. Oncological outcomes and survival did not depend on patient age, suggesting that robot-assisted surgery is a feasible surgical modality for treating operable rectal cancer and leads to age-independent post-operative outcomes in elderly patients.

PMID:33723180 | DOI:10.4103/jmas.JMAS_154_19

J Minim Access Surg. 2021 Apr-Jun;17(2):192-196. doi: 10.4103/jmas.JMAS_287_19.

ABSTRACT

BACKGROUND: We compared outcomes of en bloc stapler ligation of the renal hilum with separate Hem-o-lok polymer clip ligation of the renal vessels during laparoscopic nephrectomy (LN).

MATERIALS AND METHODS: Clinical data of patients who underwent LN for renal surgery from January 2009 to December 2015 were collected. Operation time, estimated blood loss, device malfunction rate, open conversion rate, complications and arteriovenous fistula (AVF) formation were evaluated.

RESULTS: En bloc stapler ligation and separate clip ligation were performed in 64 and 66 patients, respectively. The mean operative time was 106.8 ± 20.8 min (range: 70-165) in the en bloc stapler ligation group compared with 112.5 ± 24.1 min (range: 70-180) in the separate clip ligation group (P = 0.147). The mean estimated blood loss was 141.4 ± 124.1 ml (range: 25-600) in the en bloc stapler ligation group compared with 147.6 ± 112.4 ml (range: 25-450) in the separate clip ligation group (P = 0.767). The open conversion was required in 7/64 (10.9%) and 2/66 (3.0%) patients in the en bloc stapler ligation and separate clip ligation groups, respectively (P = 0.093). Stapler device malfunction occurred in 6 patients (9.3%). There were no statistically significant differences in overall complications (P = 0.726), minor (Grade 1-2) complications (P = 0.698) and major (Grade 3-5) complications (P = 0.716). No patient was diagnosed with AVF formation during overall median 33-month (interquartile range: 30, range: 24-96) follow-up.

CONCLUSIONS: En bloc stapler ligation of the renal hilum during nephrectomy is an effective and safe technique. Although there is no reported AVF formation with en bloc stapler ligation of the renal hilum, longer follow-up is necessary.

PMID:33723183 | DOI:10.4103/jmas.JMAS_287_19

Sci Data. 2021 Mar 15;8(1):86. doi: 10.1038/s41597-021-00874-2.

NO ABSTRACT

PMID:33723256 | DOI:10.1038/s41597-021-00874-2

J Minim Access Surg. 2021 Apr-Jun;17(2):147-152. doi: 10.4103/jmas.JMAS_294_19.

ABSTRACT

BACKGROUND AND OBJECTIVES: The objective was to assess the efficacy and safety in treating gastric stromal tumours by laparoscopy combined with gastroscopy positioning surgery.

METHODS: The randomised controlled trials (RCTs), which are about the efficacy and safety of laparoscopy combined with gastroscopy positioning surgery in treating gastric stromal tumours were searched from the PubMed (1998-1990-2018.6), Wanfang Data (1990-2018.6), China National Knowledge Infrastructure (1979-2018.6) and International Statistical Institute (1998-2018.6). The data were extracted from these trials, and the meta-analysis was made through from RevMan 5.3 software.

RESULTS: Six RCTs involving 451 patients were included in the study (227 patients in the laparoscopy combined with gastroscopy positioning group and 224 patients in laparoscopic surgery group). Compared with laparoscopic surgery group, this meta-analysis showed that laparoscopy combined with gastroscopy positioning group could shorten the post-operation hospital stay (P < 0.05) and reduce the intraoperative blood loss (P < 0.05). However, there was no significant difference in others between the two groups, such as operation time (P > 0.05), post-operative time of recovery of intestinal peristalsis (P > 0.05) and the total hospital stay (P > 0.05).

CONCLUSION: Compared with laparoscopic surgery group, the better total effect occurs in laparoscopy combined with gastroscopy positioning group for the treatment of gastric stromal tumours is better. Laparoscopy combined with gastroscopy positioning group for the gastric stromal tumours is acceptable.

PMID:33723177 | DOI:10.4103/jmas.JMAS_294_19

J Cancer Res Ther. 2021 Jan-Mar;17(1):198-203. doi: 10.4103/jcrt.JCRT_569_18.

ABSTRACT

INTRODUCTION: Neutrophil gelatinase-associated lipocalin (NGAL) has been reported to be unregulated in many cancers and to suppress tumor suppressor genes like p53 leading to cell proliferation. Studies to report its relationship with carcinoma cervix (Ca Cx) are still scant.

MATERIALS AND METHODS: Serum NGAL levels were analyzed in 30 patients of histopathologically proven locally advanced Ca Cx at the time of diagnosis and 3 weeks after standard chemoradiation by enzyme-linked immunosorbent assay. These patients underwent either brachytherapy or supplementary external beam radiotherapy (EBRT) depending on the response of treatment. The results were analyzed statistically by applying Student’s paired t-test.

RESULTS: No statistically significant difference (P > 0.05) was observed in patients of Ca Cx before and after treatment or when compared stage wise, histopathological grade wise, or response wise. But the levels were found to increase when duration of treatment was ≥8 weeks (P = 0.040) and to decrease significantly when duration of treatment was <8 weeks (P = 0.0052). The NGAL levels also increased significantly after treatment in patients who received EBRT and supplementary radiotherapy (P = 0.019) while the pre- and post-treatment difference in NGAL levels was not statistically significant in patients who received EBRT + intracavitary brachytherapy (P > 0.05).

CONCLUSION: As the duration as well as modality of treatment is quite important in Ca Cx, shorter duration associated with better results and lower NGAL levels, NGAL might prove to be a useful biomarker although further studies are needed to support the claim.

PMID:33723155 | DOI:10.4103/jcrt.JCRT_569_18