To describe the development, validation and inter-rater reliability of an instrument to measure the quality of patient decision support technologies (decision aids).
Scale development study, ...involving construct, item and scale development, validation and reliability testing.
There has been increasing use of decision support technologies--adjuncts to the discussions clinicians have with patients about difficult decisions. A global interest in developing these interventions exists among both for-profit and not-for-profit organisations. It is therefore essential to have internationally accepted standards to assess the quality of their development, process, content, potential bias and method of field testing and evaluation.
Scale development study, involving construct, item and scale development, validation and reliability testing.
Twenty-five researcher-members of the International Patient Decision Aid Standards Collaboration worked together to develop the instrument (IPDASi). In the fourth Stage (reliability study), eight raters assessed thirty randomly selected decision support technologies.
IPDASi measures quality in 10 dimensions, using 47 items, and provides an overall quality score (scaled from 0 to 100) for each intervention. Overall IPDASi scores ranged from 33 to 82 across the decision support technologies sampled (n = 30), enabling discrimination. The inter-rater intraclass correlation for the overall quality score was 0.80. Correlations of dimension scores with the overall score were all positive (0.31 to 0.68). Cronbach's alpha values for the 8 raters ranged from 0.72 to 0.93. Cronbach's alphas based on the dimension means ranged from 0.50 to 0.81, indicating that the dimensions, although well correlated, measure different aspects of decision support technology quality. A short version (19 items) was also developed that had very similar mean scores to IPDASi and high correlation between short score and overall score 0.87 (CI 0.79 to 0.92).
This work demonstrates that IPDASi has the ability to assess the quality of decision support technologies. The existing IPDASi provides an assessment of the quality of a DST's components and will be used as a tool to provide formative advice to DSTs developers and summative assessments for those who want to compare their tools against an existing benchmark.
The purpose of this note is to show how the MOVER algorithm for a ratio of two independently estimated quantities, recently published by Donner and Zou, requires modification to cope with the general ...case in which the lower and upper confidence limits for the numerator can take either sign. The MOVER (Method Of Variance Estimates Recovery) algorithm as originally formulated relates to a difference (or sum) of two independently estimated parameters. Suppose that for i = 1 and 2, θi has maximum likelihood estimate and 1 − α confidence limits Li and Ui. Then the MOVER interval for the difference θ1 − θ2, called MOVER-D is delimited by The MOVER algorithm does not explicitly take into account how the limits (Li, Ui) were calculated, but obviously for validity we require that for each parameter. It has been used extensively to derive intervals for various quantities, notably a difference of independent proportions.3 It is particularly useful for quantities derived from proportions as it preserves boundary-respecting properties. Donner and Zou provided a theoretical justification. Li and Ui are used to derive local variance estimates for θi, separately for θi ranging from Li to and from to Ui. For the lower tail of the interval for θi, the variance estimate recovered from Li is simply ( − Li)2/z2. Similarly, the variance estimate appropriate for the upper tail is (Ui − )2/z2. These recovered local variance estimates are then used to construct lower and upper limits for θ1 − θ2 in an obvious manner. Obviously these algorithms require great care with regard to signs and which limit is which.
Background: Sentinel lymph node biopsy in women with operable breast cancer is routinely used in some countries for staging the axilla despite limited data from randomized trials on morbidity and ...mortality outcomes. We conducted a multicenter randomized trial to compare quality-of-life outcomes between patients with clinically node-negative invasive breast cancer who received sentinel lymph node biopsy and patients who received standard axillary treatment. Methods: The primary outcome measures were arm and shoulder morbidity and quality of life. From November 1999 to October 2003, 1031 patients were randomly assigned to undergo sentinel lymph node biopsy (n = 515) or standard axillary surgery (n = 516). Patients with sentinel lymph node metastases proceeded to delayed axillary clearance or received axillary radiotherapy (depending on the protocol at the treating institution). Intention-to-treat analyses of data at 1, 3, 6, and 12 months after surgery are presented. All statistical tests were two-sided. Results: The relative risks of any lymphedema and sensory loss for the sentinel lymph node biopsy group compared with the standard axillary treatment group at 12 months were 0.37 (95% confidence interval CI = 0.23 to 0.60; absolute rates: 5% versus 13%) and 0.37 (95% CI = 0.27 to 0.50; absolute rates: 11% versus 31%), respectively. Drain usage, length of hospital stay, and time to resumption of normal day-to-day activities after surgery were statistically significantly lower in the sentinel lymph node biopsy group (all P<.001), and axillary operative time was reduced (P = .055). Overall patient-recorded quality of life and arm functioning scores were statistically significantly better in the sentinel lymph node biopsy group throughout (all P≤.003). These benefits were seen with no increase in anxiety levels in the sentinel lymph node biopsy group (P>.05). Conclusion: Sentinel lymph node biopsy is associated with reduced arm morbidity and better quality of life than standard axillary treatment and should be the treatment of choice for patients who have early-stage breast cancer with clinically negative nodes.
The lipid envelope of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an essential component of the virus; however, its molecular composition is undetermined. Addressing this ...knowledge gap could support the design of antiviral agents as well as further our understanding of viral-host protein interactions, infectivity, pathogenicity, and innate immune system clearance. Lipidomics revealed that the virus envelope comprised mainly phospholipids (PLs), with some cholesterol and sphingolipids, and with cholesterol/phospholipid ratio similar to lysosomes. Unlike cellular membranes, procoagulant amino-PLs were present on the external side of the viral envelope at levels exceeding those on activated platelets. Accordingly, virions directly promoted blood coagulation. To investigate whether these differences could enable selective targeting of the viral envelope in vivo, we tested whether oral rinses containing lipid-disrupting chemicals could reduce infectivity. Products containing PL-disrupting surfactants (such as cetylpyridinium chloride) met European virucidal standards in vitro; however, components that altered the critical micelle concentration reduced efficacy, and products containing essential oils, povidone-iodine, or chlorhexidine were ineffective. This result was recapitulated in vivo, where a 30-s oral rinse with cetylpyridinium chloride mouthwash eliminated live virus in the oral cavity of patients with coronavirus disease 19 for at least 1 h, whereas povidone-iodine and saline mouthwashes were ineffective. We conclude that the SARS-CoV-2 lipid envelope i) is distinct from the host plasma membrane, which may enable design of selective antiviral approaches; ii) contains exposed phosphatidylethanolamine and phosphatidylserine, which may influence thrombosis, pathogenicity, and inflammation; and iii) can be selectively targeted in vivo by specific oral rinses.
Despite the widespread application of sentinel lymph node biopsy (SLNB) for early stage breast cancer, there is a wide variation in reported test performance characteristics. A major aim of this ...prospective multicentre validation study was to quantify detection and false-negative rates of SLNB and evaluate factors influencing them.
Eight-hundred and fourty-two patients with clinically node-negative breast cancer underwent SLNB according to a standardised protocol that used a combination of radiopharmaceutical 99mTc-albumin colloid and Patent Blue V dye. SLNB was followed by standard axillary treatment at the same operation in all patients.
Sentinel lymph nodes (SLNs) were identified in 803 (96.1%) of 836 evaluable cases. The median number of SLNs removed per patient was 2 (range 1-9). There were 19 false negatives, resulting in a sensitivity of 263/282 (93.3%) and accuracy 782/803 (97.6%). SLNs were successfully identified by blue dye in 698 (85.6%), by isotope in 698 (85.6%), and by the combination of blue dye and isotope in 782 (96.0%) of 815 patients. Among 276 node positive patients, one or more positive SLNs were identified by blue dye in 251 (90.9%), by isotope in 246 (89.1%) and by the combination of blue dye and gamma probe in 258 (93.5%). Obesity, tumor location other than upper outer quadrant and non-visualisation of SLNs on the pre-operative lymphoscintiscan were significantly associated with failed localisation (p<0.001, p=0.008, p<0.001, respectively). The false-negative rate in patients with grade 3 tumors was 9.6%, compared with 4.7% in those with grade 2 tumors (p=0.022). The false-negative rate in patients who had one SLN harvested was 10.1%, compared with 1.1% in those who had multiple SLNs (three or more) removed (p=0.010).
SLNB can accurately determine whether axillary metastases are present in patients with early stage breast cancer with clinically negative axillary nodes. Both success and accuracy of SLNB are optimised by the combined use of blue dye and isotope. SLNB success decreases with increasing body mass, tumor location other than the upper outer quadrant and non-visualisation of hot nodes on the pre-operative lymphoscintiscan. This study demonstrates reduction in the predictive value of a negative SLNB in grade 3 tumors.
The purpose of this short communication is to draw attention to an efficient design for trials to evaluate desensitising agents, and an appropriate statistical analysis.
Two recent sensitivity trials ...conducted by the Bristol Dental School Clinical Trials Group are reviewed.
The methodology used was effective to establish efficacy of the products evaluated.
This methodology is recommended for wider use.
Effective clinical trial methodology enables establishment of efficacy of desensitising products leading to patient benefit.
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