In-house calibration of the international sensitivity index or calibration curve for determination of the international normalized ratio

A Preliminary Proposal for Quality Control Assessment and Harmonization of Leukocytes Morphology-structural Parameters (cell Population Data Parameters)

BACKGROUND

The cell population data (CPD) measured by Sysmex XN-9000 can be used for screening many hematological and non-hematological disorders. Since little information is available on harmonization of CPD among different instrumentation and clinical laboratories, this study aimed at assessing the current degree of CPD harmonization between separate Sysmex XN modules allocated to the same laboratory.

METHODS

A total number of 78291 data were used for verification of within-run imprecision, analyzers harmonization, reference ranges and assessment of blood sample stability of CPD parameters, including results of daily quality control testing and those generated in samples collected from blood donors and healthy volunteers.

RESULTS

Within-run imprecision of CPD parameters ranged between 0.4 and 14.1%. Good agreement was found among five different XN-modules, especially when values were adjusted after calculation of instrument-specific alignment factors. The bias of all parameters remained always lower than the reference change values in samples stored for up to 8 hours, regardless of storage temperature.

CONCLUSIONS

The imprecision of CPD parameters was acceptable, except for those reflecting the dispersion of cellular clusters. Due to the lack of reference control materials, we showed that the use of data generated on a large number of normal routine samples (i.e., a Moving Average population) may be a reliable approach for testing analyzers harmonization. Nevertheless, availability of both calibration and quality control materials for these parameters is highly advisable in the future. We finally showed that whole blood samples may be stable for up to 2-4 hours for most CPD parameters.

Calibration of self-reported oral health to clinically determined standards

OBJECTIVE

Self-report of oral health is an inexpensive approach to assessing an individual's oral health status, but it is heavily influenced by personal views and usually differs from that of clinically determined oral health status. To assist researchers and clinicians in estimating oral health self-report, we summarize clinically determined oral health measures that can objectively measure oral health and evaluate the discrepancies between self-reported and clinically determined oral health status. We test hypotheses of trends across covariates, thereby creating optimal calibration models and tools that can adjust self-reported oral health to clinically determined standards.

METHODS

Using National Health and Nutrition Examination Survey (NHANES) data, we examined the discrepancy between self-reported and clinically determined oral health. We evaluated the relationship between the degree of this discrepancy and possible factors contributing to this discrepancy, such as patient characteristics and general health condition. We used a regression approach to develop calibration models for self-reported oral health.

RESULTS

The relationship between self-reported and clinically determined oral health is complex. Generally, there is a discrepancy between the two that can best be calibrated by a model that includes general health condition, number of times a person has received health care, gender, age, education, and income.

CONCLUSION

The model we developed can be used to calibrate and adjust self-reported oral health status to that of clinically determined standards and for oral health screening of large populations in federal, state, and local programs, enabling great savings in resources used in dental care.

A practical method to calibrate self-reported adherence to antiretroviral therapy

OBJECTIVE

Self-report of antiretroviral medications adherence is inexpensive and simple to use in clinical settings but grossly overestimates adherence. We investigated methods to calibrate patients' self-reported adherence to match objectively measured adherence more closely for the purpose of developing a practical and more accurate self-reported adherence measure.

DESIGN

Longitudinal cohort design.

METHODS

Using data from 2 prospective longitudinal clinical investigations conducted at 5 HIV clinics, we examined the discrepancy between self-reported adherence and objectively measured adherence. We evaluated the relation between attitudinal measures and the degree of discrepancy and used a cross-validation approach to propose candidate items to improve adherence survey methodology.

RESULTS

Among 330 patients, self-reported adherence was consistently higher than objectively measured adherence. The best calibration models included the patient's self-reported adherence, duration of the antiretroviral regimen, and attitudinal measures (ability to take medication as instructed, believing medication can help one to live longer, whether or not it is too troublesome to take antiretrovirals, and feeling things are going the right way).

CONCLUSION

The method efficiently identified survey items to improve self-reported adherence measurement. The calibrated measure more closely approximates objectively measured adherence and is more sensitive for detecting nonadherence. These models merit evaluation in other settings.