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Interobserver variability studies in diagnostic imaging:a methodological systematic review

Objectives: To review the methodology of interobserver variability studies; including current practice and quality of conducting and reporting studies. Methods: Interobserver variability studies between January 2019 and January 2020 were included; extracted data comprised of study characteristics, populations, variability measures, key results, and conclusions. Risk of bias was assessed using the COSMIN tool for assessing reliability and measurement error. Results: Seventy-nine full-text studies were included covering various imaging tests and clinical areas. The median number of patients was 47 (IQR:23–88), and observers were 4 (IQR:2–7), with sample size justified in 12 (15%) studies. Most studies used static images (n = 75, 95%), where all observers interpreted images for all patients (n = 67, 85%). Intraclass correlation coefficients (ICC) (n = 41, 52%), Kappa (κ) statistics (n = 31, 39%) and percentage agreement (n = 15, 19%) were most commonly used. Interpretation of variability estimates often did not correspond with study conclusions. The COSMIN risk of bias tool gave a very good/adequate rating for 52 studies (66%) including any studies that used variability measures listed in the tool. For studies using static images, some study design standards were not applicable and did not contribute to the overall rating. Conclusions: Interobserver variability studies have diverse study designs and methods, the impact of which requires further evaluation. Sample size for patients and observers was often small without justification. Most studies report ICC and κ values, which did not always coincide with the study conclusion. High ratings were assigned to many studies using the COSMIN risk of bias tool, with certain standards scored ‘not applicable’ when static images were used. Advances in knowledge: The sample size for both patients and observers was often small without justification. For most studies, observers interpreted static images and did not evaluate the process of acquiring the imaging test, meaning it was not possible to assess many COSMIN risk of bias standards for studies with this design. Most studies reported intraclass correlation coefficient and κ statistics; study conclusions often did not correspond with results

Baseline radiomics features and MYC rearrangement status predict progression in aggressive B-cell lymphoma

We investigated whether the outcome prediction of patients with aggressive B-cell lymphoma can be improved by combining clinical, molecular genotype, and radiomics features. MYC, BCL2, and BCL6 rearrangements were assessed using fluorescence in situ hybridization. Seventeen radiomics features were extracted from the baseline positron emission tomography–computed tomography of 323 patients, which included maximum standardized uptake value (SUV(max)), SUV(peak), SUV(mean), metabolic tumor volume (MTV), total lesion glycolysis, and 12 dissemination features pertaining to distance, differences in uptake and volume between lesions, respectively. Logistic regression with backward feature selection was used to predict progression after 2 years. The predictive value of (1) International Prognostic Index (IPI); (2) IPI plus MYC; (3) IPI, MYC, and MTV; (4) radiomics; and (5) MYC plus radiomics models were tested using the cross-validated area under the curve (CV-AUC) and positive predictive values (PPVs). IPI yielded a CV-AUC of 0.65 ± 0.07 with a PPV of 29.6%. The IPI plus MYC model yielded a CV-AUC of 0.68 ± 0.08. IPI, MYC, and MTV yielded a CV-AUC of 0.74 ± 0.08. The highest model performance of the radiomics model was observed for MTV combined with the maximum distance between the largest lesion and another lesion, the maximum difference in SUV(peak) between 2 lesions, and the sum of distances between all lesions, yielding an improved CV-AUC of 0.77 ± 0.07. The same radiomics features were retained when adding MYC (CV-AUC, 0.77 ± 0.07). PPV was highest for the MYC plus radiomics model (50.0%) and increased by 20% compared with the IPI (29.6%). Adding radiomics features improved model performance and PPV and can, therefore, aid in identifying poor prognosis patients

Enabling meta-analysis in systematic reviews on carpal tunnel syndrome

Possible solutions to the problems of clinical heterogeneity of outcome measures and inadequate reporting of results for randomized controlled trials (RCTs) on carpal tunnel syndrome (CTS) are presented. Meta-analysis was impeded by these problems in 2 systematic reviews concerning conservative and surgical treatment options for CTS. A solution to the problem of inadequate data presentation is to add explicit information on minimal requirements with regard to data presentation to guidelines for the reporting of studies. To resolve the problem of clinical heterogeneity of the outcomes there should be consensus on the (validated) outcomes that should be used in RCTs. For CTS there is little evidence available on the reliability, validity, and responsiveness to change of the commonly used outcomes in RCTs. Resolving both problems will increase the comparability of RCTs, enabling the calculation of a pooled estimate of effect in a meta-analysi

Health-related quality of life in chronic refractory reflex sympathetic dystrophy (Complex regional pain syndrome type I)

The aim of this study was to find out which aspects of health-related quality of life (HRQL), measured with generic instruments, are important to patients with reflex sympathetic dystrophy (RSD) affecting the arm or leg. The Sickness Impact Profile 68 (SIP68), the Nottingham Health Profile (NHP), and the EuroQol-5D (EQ-5D) were completed by 54 patients suffering from RSD (33 arm, 21 leg). The scores of the three questionnaires for patients with an affected arm or leg are presented. Aspects relevant to patients with RSD of the arm include the NHP1 dimensions of pain (mean score: 63%), sleep (58%), and energy (45%), and the EQ-5D dimensions of pain (67% extreme), usual activities (76% some problems), and self care (76% some problems). Aspects relevant to patients with RSD of the leg include the SIP68 dimensions of social behavior (51%) and mobility control (46%), the NHP 1 dimensions of pain (mean score: 86%), mobility (54%), energy (53%), and sleep (52%), and the EQ-5D dimensions of mobility (81% some problems), pain (71% extreme), and usual activities (71% some problems). The study showed that applying generic HRQL instruments and measuring treatment effect with the dimensions scoring high provides a responsive instrument which at the same time gains information concerning dimensions not maximally responsive to a specific disease. Some dimensions which, on the basis of their label, might be expected to be important were found not to be so. After using this approach, clinicians can more directly focus treatment on specific areas that have been shown to affect a patient's HRQL. (C) U.S. Cancer Pain Relief Committee, 2000

An objective and standardized test of foot function: Normative values and validation in patients with reflex sympathetic dystrophy

Objective: To describe and obtain normative values for an objective and standardized test of foot function, and to validate the test in patients with impaired function of 1 leg. Design: A series of 4 standardized and objectively measured subtests, representing common foot activities in daily living, was devised. Setting: University hospital. Participants: Normative values were obtained for 100 healthy patients between 20 and 70 years of age. For validation purposes, the test was also performed by 20 patients diagnosed with reflex sympathetic dystrophy of 1 foot. Main Outcome Measures: Several basic aspects of individual foot function were evaluated: (1) forward and backward shifting (FBS) of a foot panel; (2) lateral shifting (LS) of a foot panel; (3) alternately touching 2 bells (TB); and (4) depressing a pedal (DP). (The tests were performed while seated; hence, they are applicable to patients unable to walk.) Comparison with results on a battery of other clinical function tests was assessed. Results: The intrarater and interrater reliabilities of the test were high (eg, intrarater correlation coefficients ranged from .74 to .93; interrater from .85 to .99). Results were influenced by sex and dominance, but were not influenced by height, weight, or shoe size. Age and leisure activities involving foot function influenced 1 subtest only (depressing a pedal). Results of the affected side in patients were higher than normative values although, to a lesser extent, the same was true for the unaffected side. Footboard results did not correlate with results of other function tests, except myometry, suggesting that it provides additional information. In contrast to the other tests, and like myometry, the footboard distinguished patients who were crutch dependent from those who were not. Conclusion: The footboard is a valuable addition to current tests for assessing foot function

The diagnostic value of digital rectal examination in primary care screening for prostate cancer: A meta-analysis

Objective. This systematic review examines the diagnostic value of the digital rectal examination (DRE) for the diagnosis of prostate cancer. Method. Only studies relating to unselected populations and using either biopsy or surgery as the reference standard were included. The methodological quality of the studies was used in an attempt to explain differences between studies. Results. Fourteen studies were eligible for selection, of which five complied with the predetermined list of 'good-quality' requirements. Between study heterogeneity was high, even within the group of high-quality studies, and could not be explained by the registered indicators of methodological quality. Conclusions. In this setting, the DRE appears to be a test with a high specificity and negative predictive value, but a low sensitivity and positive predictive value. Neither a positive nor a negative test result is sufficient to enable conclusions without further confirmation