Method Agreement Analysis

Zou GY. Estimated confidence interval for Bland-Altman limits of compliance with multiple observations per person. Med Res Stat Methods. 2013;22:630. with the square root of the overall variance that gives an estimate of the standard deviation for use within the conventional Bland-Altman limit of the agreement formula. One of the most obvious advantages of next-generation optical biometrics techniques such as LENSTAR and IOLMaster is the potential to minimize measurement discrepancies due to operator experience. Kielhorn et al.31 have shown that the experienced and inexperienced operators of the IOLMaster have made essentially similar measures for the performance of the IOL. In constrast, Goel et al.32 reported that the variation in AL between experienced and non-experimental ultrasonic biometric operators was ten times greater than that of IOLMaster. In overcrowded ophthalmic clinics around the world, we see obvious benefits in the introduction of low-coherence optical reflectometers (OLCCs) or partial coherence interferometry (ICP) in consultation meetings. Cataract patients would experience shorter wait times; there is no risk of contamination or the need for anesthetic eye drops. These improvements are welcomed by patients, as hospital visits are often tedious and can be costly and uncomfortable in the event of unexpected side effects. The strong agreement between LENSTAR and IOLMaster for observed eye variables indicates the biometric equivalence of the measurements of both.

On the other hand, it seems that the difference in speed between them has the potential to save a lot of time on a large number of patients (60 minutes out of 40 patients) when IOLMaster is used. The difference is obtained because LENSTAR simultaneously calculates the power, IOL and K values, so that if any of these variables detect marginal measurements, you must repeat the entire procedure. IOLMaster does not have this problem because the measurements are evaluated sequentially. Nevertheless, LENSTAR`s ability to measure additional variables such as the central thickness of the cornea and lenses, which is lacking in IOLMaster, may be useful for ophthalmologists who need such information. It is interesting to note that the compliance limits also from the model in Eq. (2) can be calculated at the following expression for the differences of stevens et al. [14, 29] develops the probability of the agreement (PoA) method as an alternative to the limits of the agreement approach, which has the advantage of taking into account two different types of bias and uneven accuracy between devices. Proportional distortion, where the extent of disagreement depends on the actual value in each subject, is considered in addition to additive distortions, and this information can be used to clarify the various sources of disagreement if the devices do not agree. The PoA method provides a flexible and informative summary of the agreement, but the method does not currently adapt to disruptors (for example. B activity in our COPD study) and is therefore not yet as widespread as other alternatives. For more details on this method, see the additional file. Parker RA, Weir CJ, Rubio N, Rabinovich R, Pinnock H, Hanley J, et al.

Application of Mixed Effects Compliance Limitations in the presence of multiple sources of variability: an example from the comparison of several breathing frequency measurement devices in COPD patients. PLoS One. 2016;11 (12):e0168321. Parker RA. Contract analysis in the field of complex variability: agreement on fluoride absorption measures 18F.