Linear regression analysis
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Springer series in statistics
1st ed. 568 s.
Vyšetrili sme 79 pacientov (n = 79) s primárnou a sekundárnou osteoporózou, z toho 31 mužov (nM = 31) vo veku 31–61 rokov a 48 žien (nF = 48) vo veku 33–65 rokov. U týchto pacientov sme sledovali aminoterminálny telopeptid kolagénu I organickej kostnej matrix (NTx) v 24- (NTx 24) a v 2hodino- vej rannej (NTx 2) diuréze (od 6.00–8.00 h). Cieľ práce: zodpovedať otázky: 1. Je štatisticky významná korelácia medzi hodnotami NTx v 24- a v 2hodinovej diuréze u pacientov s osteoporózou? 2. Je štatisticky významný rozdiel v hladine NTx v 24- a v 2hodinovej diuréze u toho istého pa- cienta? 3. Je 2hodinová diuréza pre stanovenie hladín NTx u pacientov s osteoporózou presnejšia než doteraz používaný odber prvého alebo druhého ranného moču, ktorý sa odoberá v ktorúkoľvek rannú hodinu? Štatistická analýza: K testovaniu normality rozdelenia v každom súbore sme použili d’Agostinov test. Jednosmernú závislosť náhodnej premennej y (NTx 2) od nezávislej premennej x (NTx 24) sme vyjadrili pomocou lineárnej regresie. Výsledky: Medzi hodnotami NTx 24 (os x) a NTx 2 (os y) sa zistila štatisticky významná (p < 0,001) pozitívna korelácia (ženy: r = 0,884, muži: r = 0,593). V súbore mužov a žien sa zistili štatisticky významne vyššie hodnoty NTx 2 ako NTx 24, čo je podmienené cirkadiánnym biorytmom hladiny NTx, ktorá dosahuje exkrečné maximum medzi 3. a 7. hodinou rannou. Referenčné hodnoty NTx 2 vypočítané z rovnice lineárnej regresie [y = a + bx, y = NTx 2, x = NTx 24, (a, b) – regresné koeficienty] vykazujú užší interval (ženy: 22,96–46,48 nmol/mmol kreatininu, muži 29,52–47,16 nmol/mmol kreatininu) ako referenčné hodnoty pre prvý ranný moč uvádzané výrobcom kitov NTx (OSTEX, USA) – (ženy: 5–65, muži: 10–72 nmol/nmol kreatininu). Záver: 1. Medzi hodnotami NTx 24 a NTx 2 sa zistila štatisticky významná pozitívna korelácia. Obidva zbery moču sa môžu používať k stanoveniu hladín NTx 2). Zavedenie dvojhodino- vej rannej diurézy pre stanovenie hladín NTx zmenší rozsah kolísania hodnôt NTx pri jeho opako- vanom vyšetrení a spresní výpovednosť jeho hodnôt.
The authors examined 79 patients (n = 79) with primary and secondary osteoporosis incl. 31 men (nM = 31) aged 31–61 years and 48 women (nF = 48) aged 33 to 65 years. In these patients the authors investigated the aminoterminal telopeptide of collagen I of the organic bone matrix (NTx) on the 24-hour (NTx 24) and 2-hour morning (NTx 2) diuresis (from 6 to 8 a.m.). Objective: to find a reply to the question 1. Is there a statistically significant correlation between values BTx in the 24-hour and 2-hour diuresis in patients with osteoporosis? 2. Is there a statistically significant difference in the level of NTx in the 24-hour and 2-hour diuresis in the same patient? 3. Is the 2-hour diuresis more accurate for the assessment of levels of NTx in patients with osteoporosis than the hitherto used collection of the first or second urine sample collected at any time in the morning? Statistical analysis: for testing of the normality of distribution in each group the authors used d’Agostin’s test. The one way relationship of a random variable y (NTx 2) on the independent variable x (NTx 24) was expressed by linear regression. Results: Between values NTx (axis x) and NTx 2 and NTx 1 (axis y) a significant (p < 0.001) positive correlation was found (women r = 0.884, men r = 0.593). In the group of men and women significantly higher values of NTx 2 were found than NTx 24 which is due to the circadian biorhythm of the NTx level which reaches its excretory maximum between 3 and 7 a.m. The reference value of NTx 2 calculated from the equation of linear regression [y = a + bx, b = NTx 2, x = NTx 24, (a, b) – regression coefficients] have a narrower interval (women: 22.96–46.48 nmol/mmol creatinine, men 29.52–47.16 nmol/mmol creatinine than the reference value for the first morning urine given by the manufacturer of NTx kits (OSTEX USA) – women 5–65, men 10–72 nmol/mmol creatinine). Conclusion: 1. Between values of NTy 24 and NTx 2 a significant positive correlation was found. Both urine samples can be used for assessment of NTx levels. 2. Introduction of two-hour morning diuresis for assessment of NTx levels reduces the range of variation of NTx levels during repeated examinations and makes the information provided by the values more accurate.
- MeSH
- diuréza MeSH
- dospělí MeSH
- kostní denzita MeSH
- kreatinin moč MeSH
- lidé středního věku MeSH
- lidé MeSH
- osteoporóza MeSH
- regresní analýza metody MeSH
- vápník MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- srovnávací studie MeSH
... Installation and use of R 9\n\n2.3 Basic operations 11\n\n2.4 Data frames 18\n\n3 Exploratory data analysis ... ... plots 40\n\n3.5.9 Plots with whiskers 40\n\n3.5.10 Curves 41\n\nV\n4 Statistical modelling\n\n4.1 Regression ... ... model 43\n\n4.2 General linear model 45\n\n4.3 Generalized linear model 47\n\n4.4 Searching for the ... ... n5 The first trial\n\n5.1 An example 61\n\n5.2 EDA 61\n\n5.3 Presumed model 63\n\n5.4 Statistical analysis ... ... 108\n\n8.3 Weighted regression 116\n\n8.4 Multiple regression 120\n\nVI\n8.5 Two-way A NOVA 132\n\n8.6 ...
First edition x, 245 stran : ilustrace ; 24 cm
- Konspekt
- Biologické vědy
- NLK Obory
- biologie
- statistika, zdravotnická statistika
- knihovnictví, informační věda a muzeologie
- NLK Publikační typ
- kolektivní monografie
BACKGROUND: Intensive selfmonitoring is an important and cost-demanding part of diabetes treatment. Continuous glucose monitoring (CGM) using transcutaneous sensors offers "real time" information on glycemia. In the present study, we assessed the therapeutic efficacy of CGM on metabolic control using two different statistical methods: linear regression and "survival analysis". OBJECTIVES: (1) to assess the therapeutic efficacy of CGM on metabolic control using two different statistical methods: linear regression and survival analysis; (2) to demonstrate the particular advantages of each statistical method. METHODS: A total of 42 persons with diabetes mellitus treated by means of an insulin pump participated in this study. According to the means of selfmonitoring persons with diabetes were divided into two groups: 1. intervention group of 17 persons using CGM, 2. control group of 25 persons using a glucometer. Each person was followed for a period of three months. At the beginning of the study and at the end of each month HbA1c was determined. RESULTS: Both the regression analysis and survival analysis brought evidence of significant changes of the HbA1c in either of the groups. The method of linear regression enables to analyse the evolution of HbA1c in each individual person followed by comparison of the groups. The survival analysis demonstrated that the probability of HbA1c decrease to the predefined level as well as its further maintaining at this level was higher in the CGM group. The mean time interval necessary to HbA1c decrease was shorter in the CGM group. CONCLUSIONS: The efficacy of CGM was demonstrated. In addition to linear regression, survival analysis appears to be an useful complementary method in the statistical evaluation of the treatment efficacy.
- MeSH
- ambulantní monitorování MeSH
- analýza přežití MeSH
- diabetes mellitus 1. typu farmakoterapie krev MeSH
- dospělí MeSH
- financování organizované MeSH
- glykovaný hemoglobin analýza MeSH
- inzulinové infuzní systémy MeSH
- lidé středního věku MeSH
- lidé MeSH
- lineární modely MeSH
- mladý dospělý MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
... Linear Regression and the Logistic Regression Model 1 -- 1.1 Regression Assumptions 4 -- 1.2 Nonlinear ... ... 36 -- 2.5 Conclusion: Summary Measures for Evaluating the -- Logistic Regression Model 41 -- 3. ... ... Interpreting the Logistic Regression Coefficients 41 -- 3.1 Statistical Significance in Logistic Regression ... ... Analysis 43 -- 3.2 Interpreting Unstandardized Logistic Regression -- Coefficients 48 -- 3.3 Substantive ... ... Polytomous Logistic Regression and Alternatives to -- Logistic Regression 91 -- 5.1 Polytomous Nominal ...
Sage university papers series Quantitative applications in t he social sciences ; No. 07-106
2nd ed. viii, 111 s. : il.
