Reference intervals, etc.

Wilkinson, Ian B.; Raine, Tim; Wiles, Kate; Goodhart, Anna; Hall, Catriona; O’Neill, Harriet

doi:10.1093/med/9780199689903.003.0017

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…sample size, age distribution, ethnic background, concomitant medications), and different statistical methods applied make it difficult to directly compare RIs from different studies, even if the studies all use LC-MS/MS ( 13 ). Also preanalytical procedures can increase variation of results between laboratories and should be considered when interpreting RIs ( 27 , 28 , 29 ). Preanalytical procedures followed a strict procedure in our study.…”

Section: Discussionmentioning

confidence: 99%

Age- and sex-adjusted reference intervals for steroid hormones measured by liquid chromatography–tandem mass spectrometry using a widely available kit

Kunz,

Wang,

Ferrari

et al. 2023

Endocrine Connections

View full text Add to dashboard Cite

Objective Measurements utilizing commercially available sets of reagents for determination of steroid hormone profiles by liquid chromatography–tandem mass spectrometry (LC-MS/MS) have become increasingly important for routine laboratories. However, method-specific publications of reference intervals obtained from sufficiently large studies are often missing. Methods After validation of performance characteristics, a widely available kit for steroid analysis by LC-MS/MS was used to measure concentrations of 15 endogenous steroids (aldosterone, cortisol, cortisone, corticosterone, 11-deoxycortisol, 21-deoxycortisol, dehydroepiandrosterone sulfate, estradiol, testosterone, androstenedione, dihydrotestosterone, dehydroepiandrosterone, 17-hydroxyprogesterone, 11-deoxycorticosterone, progesterone) in more than 500 blood samples from a population-based study. While randomly selected from a larger cohort, the samples equally represented both sexes and covered a wide range of adult age groups. Age- and sex-specific reference intervals were calculated, and correlation with BMI was assessed. Results Performance characteristics of the assay matched expectations for 9 of 15 steroids. For most of them, reference intervals obtained from our study population were comparable to those reported by others, with age and sex being the major determinants. A sex-specific correlation with BMI was found for seven steroids. We identified limitations regarding sensitivity of the method for quantification of progesterone in males and postmenopausal females. Concentrations of aldosterone, 21-deoxycortisol, estradiol, 11-deoxycorticosterone, and dihydrotestosterone could not be quantified in a large percentage of samples. Conclusions The reference intervals for nine steroids will support meaningful interpretation for steroid profiles as measured by a widely used kit for LC-MS/MS-based quantification. Laboratories using such kits must be aware of potential limitations in sensitivity for some steroids included in the profile. Significance Statement Quantification of steroid hormones is a cornerstone for diagnosis of several diseases. Commonly used immunoassays have limitations in specificity. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) is a promising alternative, particularly if methods are harmonized across laboratories. The use of kits from commercial suppliers might support this. Clinical interpretation of steroid concentrations requires availability of appropriate reference intervals (RIs), but studies on RIs reported in the literature differ in preanalytical and analytical procedures. Here, we provide RIs for steroids measured by a widely available kit under preanalytical conditions mirroring common clinical practice. Such RIs might facilitate interpretation for those using the same method and comparable conditions in clinical routine.

show abstract

Section: Discussionmentioning

confidence: 99%

Age- and sex-adjusted reference intervals for steroid hormones measured by liquid chromatography–tandem mass spectrometry using a widely available kit

Kunz,

Wang,

Ferrari

et al. 2023

Endocrine Connections

View full text Add to dashboard Cite

show abstract

“…The standardized score of a dog is the Z‐score, indicating how many SDs the dog's value is away from the expected mean of the normal population; in this case, only exceeding 2 SDs is relevant 27 . Thus, a score greater than 2 indicates the dog's value is outside of the upper extreme of 95% of the normal population (2 SDs) and could therefore be interpreted as abnormal 21 . Only reference values from previous experimental work in canine models are currently available for the distal sensor location.…”

Section: Discussionmentioning

confidence: 99%

“…For each dog ( i ), the standardized score of the distal percentage time pH ≤4 was calculated against the mean and SD for the respective variable from 21 normal dogs ( x ) as reported by McMahon 20

Standardized parameter score ((), i) goodbreak= \frac{({Measurement}_{i} - {mean}_{x})}{{SD}_{x}}

Based on the Gaussian distribution of the variable for normal dogs in McMahon's study, 95% of measurements for all normal dogs would be contained within ± 1.96 SDs of the mean x , thus, a variable score >2 would be outside the upper reference limit and considered abnormal 21 . This is akin to documenting whether or not a dog is above the outer limit of the reference interval, which is established from the mean ± 1.96 SD 22 .…”

Section: Methodsmentioning

confidence: 99%

Quantification of gastroesophageal regurgitation in brachycephalic dogs

Appelgrein

Hosgood

Thompson

et al. 2022

Veterinary Internal Medicne

View full text Add to dashboard Cite

Background Gastroesophageal reflux and regurgitation occurs in brachycephalic dogs, but objective assessment is lacking. Objectives Quantify reflux in brachycephalic dogs using an esophageal pH probe and determine the association with scored clinical observations. Animals Fifty‐one brachycephalic dogs. Methods Case review study. Signs of respiratory and gastrointestinal disease severity were graded based on owner assessment. An esophageal pH probe with 2 pH sensors was placed for 18‐24 hours in brachycephalic dogs that presented for upper airway assessment. Proximal and distal reflux were indicated by detection of fluid with a pH ≤4. The median reflux per hour, percentage time pH ≤4, number of refluxes ≥5 minutes and longest reflux event for distal and proximal sensors were recorded. Association of preoperative respiratory and gastrointestinal grade, laryngeal collapse grade, and previous airway surgery with the distal percentage time pH ≤4 was examined using 1‐way ANOVA. Results A total of 43 of 51 dogs (84%; 95% confidence interval 72‐92) displayed abnormal reflux with a median (range) distal percentage time pH ≤4 of 6.4 (2.5‐36.1). There was no significant association between the distal percentage time pH ≤4 and respiratory grade, gastrointestinal grade, laryngeal collapse grade, or previous upper airway surgery. Conclusions and Clinical Importance The occurrence of reflux is not associated with owner‐assessed preoperative respiratory and gastrointestinal grade, laryngeal collapse grade, and previous airway surgery. Esophageal pH measurement provides an objective assessment tool before and after surgery.

show abstract

“…They are the most typical type of decision support tool used to analyze numerical pathology ndings. The quality of the reference intervals can have just as much of an impact on the interpretation of laboratory results as the quality of the actual result because these intervals can be used to compare laboratory results (3). Reference intervals used in other countries could not be used as such in Nepal without their calibration for the Nepalese population.…”

Section: Introductionmentioning

confidence: 99%

Establishment of Reference Intervals for the routine Liver function tests in the adult population of Gandaki province, Nepal

Sharma

Pokharel

Dhakal

2023

Preprint

View full text Add to dashboard Cite

Background: International Federation for Clinical Chemistry and Laboratory Medicine (IFCC) guidelines recommend every laboratory establish its own reference intervals (RIs) to promote precision medicine. However, Nepalese diagnostic laboratories rarely establish RIs for routine biochemical test parameters and use them while reporting the test results. Thus, there is a dearth of population and method-specific RIs of several biochemical parameters in Nepal. This study thus aimed to establish dry chemistry-based RIs of routine LFTs for the adult population of Gandaki Province, Nepal. Materials and Methods: This was a priori method for the establishment of RIs which enrolled a cohort of 272 healthy adults from the Gandaki Province of Nepal to establish RIs of LFTs as per the recommendation of IFCC guidelines. The RIs were estimated using non-parametric statistical tools and presented as RI based on the percentile method. Our established RIs were compared to those supplied by reagent kit manufacturers by comparing calculated out-of-range (OOR) values. Results: Total and sex-specific reference intervals were established for the routine liver function test parameters. For general population established RIs include: Total protein 68.0-69.0g/L; Albumin 39.0-52.0g/L; Globulin 27.0-42.0g/L; A/G ratio 1.1-1.8; total bilirubin 5.13-25.65𝝁mol/L; Unconjugated bilirubin 1.71- 17.10 𝝁mol/L; Conjugated bilirubin 0.00-10.26 𝝁mol/L; AST 20.0-43.2U/L; ALT 11.0-53.0 U/L; AST/ALT ratio 0.7-2.1; ALP 42.0-135.4U/L. The overall 95% RI s for these parameters showed significant sex differences (p < 0.05) for Albumin, Globulin, A/G ratio, AST, ALT and AST/ALT ratio. The RIs established for LFT parameters were found to vary significantly according to the age and sex of the study subjects. Moreover, established RIs in this study also differed from the currently adopted external RIs while observing out-of-range results. Conclusion: The present study for the first time established the dry chemistry-based RIs of routine LFTs for the adult population of Gandaki Province of Nepal. This RIs were different from the currently adopted external RIs supplied by manufacturers. Hence the diagnostic lab from Gandaki province is recommended to follow this RI while reporting the results of routine liver function tests.

show abstract

Reference intervals, etc.

Abstract: This chapter explores reference intervals, including statistics in medicine, biochemistry reference intervals, haematology reference intervals, drug therapeutic ranges in plasma, and important drug interactions.

Cited by 4 publications

References 0 publications

Age- and sex-adjusted reference intervals for steroid hormones measured by liquid chromatography–tandem mass spectrometry using a widely available kit

Age- and sex-adjusted reference intervals for steroid hormones measured by liquid chromatography–tandem mass spectrometry using a widely available kit

Quantification of gastroesophageal regurgitation in brachycephalic dogs

Establishment of Reference Intervals for the routine Liver function tests in the adult population of Gandaki province, Nepal

Contact Info

Product

Resources

About