• 제목/요약/키워드: Paired T-Test

검색결과 2,795건 처리시간 0.031초

피부자극이 혈액투석환자의 동정맥루 천자시 동통감소에 미치는 영향 (The Efect of Cutaneus Stimulation on AV Fistula Puncture Pain of Hemodialysis Patients)

  • 박정숙
    • 대한간호
    • /
    • 제33권1호
    • /
    • pp.37-51
    • /
    • 1994
  • The cutaneous stimulation is an independent nursing intervention used in various painful conditions, and is explained by gate control theory. This study was aimed at identifying the effect of cutaneous stimulation on reduction of arteriovenous fistula puncture pain of hemodialysis patients. One group repeated measurement post test research was designed. Forty-five hemodialysis patients who received arteriovenous fistula puncture regulary in hemodialysis units of an attacted D hospital to K university have been studied from August 16 to 21, 1993. First the arteriovenous fistula puncture pain of control period was measured, and then the arteriovenous fistula puncture pain of experimental period(with cutaneous stimulation) was measured. The instrument used for this study were visual analogue pain scale as subjective pain measurement, objective pain behavior checklist and Spielberger's Trait Anxiety Inventory as intervening variables. Analysis of data was done by use of paired t-test, t-test, ANOVA and Perarson correlation coefficient. The results of this study were summarized as follows; 1) The first hypothesis that the subjective pain score of arteriovenous fistula puncture pain in experimental period(with cutaneous stimulation) will be lower than in control period was partly supported. The subjective pain score of arterial line was rejected(paired t=-0.28, p=0.77) and the subjective pain score of venous line was supported(paired t=2.61, p=0.01). 2) The second hypothesis that the objective pain behavior score of arteriovenous fistula pain in experimental period(with cutaneous stimulation) will be lower than in control period was rejected(arterial line paired t=-0.45, p=0.65; venous line paired t=-0.36, p=0.72). 3) The third hypothesis that the cardiopulmonary signs of arteriovenous fistula puncture pain in experimental period(with cutaneous stimulation) will be lower than in control period was rejected(pulse paired t=-0.8, p=0.42; systolic BP paired t=0.98, p=0.33; diastolic BP paired t=0.43, p=0.66). Further experimental studies with simple intravenous injection patients will be recommended in order to identify the effect of cutaneous stimulation.

  • PDF

쌍체비교와 독립비교에 대한 통계적인 고찰 (A Statistical Approach to Paired versus Group Comparisons)

  • 김태민;김상부
    • 응용통계연구
    • /
    • 제19권2호
    • /
    • pp.231-240
    • /
    • 2006
  • 일반적으로 쌍체 비교(paired comparison 또는 paired t test)가 효과적인 쌍으로의 구획을 통하여 소위 독립비교(group comparison)라고 일컫는 독립 이표본 t 검정(two-sample t test)보다 정밀한 결과를 제공하는 것으로 알려져 있다. 본 논문에서는 이와 같은 사실을 통계적으로 됫받침하기 위하여 두 방법의 정밀도를 보다 정량적으로 비교하였다. 독립 비교와 쌍체 비교가 각각 일원배치법과 이원배치법 (특히, 임의화 블록 설계법)의 특수한 경우이므로 각각에 상응하는 신뢰구간의 길이의 비로 정의된 비교 통계량은 분산분석의 통계량으로 표현된다. 다시 말해서, 이 통계량은 t 와 F 분포함수로 표현되므로 쉽게 독립비교와 쌍체비교의 정밀도를 비교할 수 있다. 실제로, 자주 쓰이는 유의수준에서는 쌍체표본 내에 구획 간의 유의한 변동이 있으면 쌍체비교가 독립비교보다 정밀할 가능성이 더 높다.

Effect of 2Dimesion and 3Dimension Images on Human Factors

  • Kim, Jung-Ho;Kwon, Soon Chul;Son, Kwang Chul;Sohn, Chae Bong;Lee, Seung Hyun
    • International Journal of Internet, Broadcasting and Communication
    • /
    • 제6권2호
    • /
    • pp.13-16
    • /
    • 2014
  • This study aims to examine the effects of watching 2D and 3D images on the blink rate. Regarding the image watch, their blink rate for 2D and 3D images was separately checked for 1 minute in the 1m distance, before the watch, after 15 minutes of watch, and after 30 minutes of watch. About the change of their blink rate in the 2D image watch, it tended to become higher than that before watching the image; however, there was no statistical significance (paired t-test, p=0.106, p=0.062). And in the 2D image watch, it tended to increase in comparison between after 15 minutes and after 30 minutes, but there was no statistical significance (paired t-test, p=0.623). Meanwhile, about the change of their blink rate in the 3D image watch, it tended to decrease statistically significantly both after 15 minutes and after 30 minutes when compared with that before watching the image (paired t-test, p=0.000, p=0.000). In the 3D image watch, it tended to increase in comparison between after 15 minutes and after 30 minutes; however, there was no statistical significance (paired t-test, p=0.867).

The estimation of cholesterol intake in elderly: reliability and validity of short, Semi-Quantitative Food Frequency Questionnaire (SQ-FFQ)

  • Nindya, Triska Susila;Mahmudiono, Trias;Rachmah, Qonita
    • Journal of Nutrition and Health
    • /
    • 제54권1호
    • /
    • pp.95-103
    • /
    • 2021
  • Purpose: High intake of cholesterol leads to cardiovascular disruption. Estimating the actual intake of cholesterol can be beneficial for nutrition intervention. This research aimed to develop Semi-Quantitative Food Frequency Questionnaire (SQ-FFQ) to estimate cholesterol intake and analyze its reliability and validity. Methods: SQ-FFQ was developed by sorting high cholesterol food items in Indonesian food database and food items' availability. A total of 30 older adults were randomly chosen from Public Health Center in Jagir District, Surabaya, Indonesia to test its validity. Reliability test was done by measuring the same developed SQ-FFQ in one-month period, while validity test was done by comparing SQ-FFQ results with 6-days food record. Statistical analysis used for reliability test was paired t-test, the Intra-class Correlation Coefficient (ICC), and Cronbach's α to measure the internal consistency. Meanwhile, validity of developed SQ-FFQ was analyzed using paired t-test and Bland-Altman. Results: Reliability of 2 administered SQ-FFQs showed a good agreement based on paired t-test analysis (p = 0.200), ICC (0.609), and Cronbach's α (0.757). Strong agreement was found in most of food items, but agreements for egg yolk and fried duck were poor. Significant difference was found between those food items (p = 0.001 vs. p < 0.001, respectively) with mean difference were -25.3 mg and 46.2 mg. Validity of developed SQ-FFQ2 compared to 6-days food diary records also found a strong agreement based on paired t-test and the Bland-Altman analysis. Conclusion: This baseline research provides a reasonably valid and repeatable measure of cholesterol intake estimation that can be widely used in nutrition and public health study, especially in Indonesia. No study has been conducted in Indonesia on the development of tools to estimate the cholesterol intake.

Radiographic changes of mandibular cortical bone in bisphosphonate drug holiday

  • Lee, Dae-Hoon;Seo, Ja-In;Song, Seung-Il;Lee, Jeong-Keun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제48권4호
    • /
    • pp.219-224
    • /
    • 2022
  • Objectives: There have been few studies to date on the residual effect of bisphosphonate. This study investigated the radiographic changes of mandibular cortical thickness upon bisphosphonate drug holiday. Materials and Methods: This retrospective study includes 36 patients diagnosed with MRONJ (medication-related osteonecrosis of the jaw) at Ajou University Dental Hospital in 2010-2021. All patients stopped taking bisphosphonate under consultation with the prescribing physicians. Panoramic radiographs were taken at the start of discontinuation (T0), 12 months after (T1), and 18 months after (T2) discontinuation of bisphosphonate, respectively. Mental index and panoramic mandibular index were calculated using Ledgerton's method. Paired t-tests were used to analyze differences over time. Results: The difference in indices (mental index and panoramic mandibular index) between T0 and T1 was not statistically significant (paired t-test, P>0.05). However, the difference in these indices between T1 and T2 was statistically significant (paired t-test, P<0.05). Conclusion: The cortical thickness of the mandible decreased in the late stage (after 18 months) as observed by panoramic radiograph.

대한치주과학회지에 게재된 학술논문의 통계분석에 대한 평가 (Evaluation of Statistical Analysis of Articles in Journal of Korean Academy of Periodontology)

  • 남민숙;전창길;한경윤;김병옥;신광용
    • Journal of Periodontal and Implant Science
    • /
    • 제30권3호
    • /
    • pp.699-707
    • /
    • 2000
  • The purpose of this study was to analyze the statistical errors of articles in the Journal of Korean Academy of Periodontology from 1973 to 1999. Of the 662 articles examined, 263 were included which analyzed the data. They were classified into 2 groups with time lapse; group 1: 1973∼1989, group 2: 1990∼1999. Authors made checklists for analyzing the data and detecting the errors and analyzed them with professional statistician. The results were as follows: 1. Of 263 atricles which applied statistical method, 40(19.3%) was in group 1, 223(49.0%) in group2. 2. In the number of statistical method applied, 170(64.6%) were analyzed with 1 statistical method, 73(27.8%) with 2 methods, 18(6.8%) with 3 methods, and 2(0.8%) with 4 methods 3. The number of statistical methods applied was 14, and they were applied in order of 119 of ANOVA, 72 of Student t-test, 63 of Paired t-test, 36 of CORRELATION, and 21 of Mann- Whitney U test. 4. In 87(33.1%) of 263 articles and in 18 error items, statistical errors were found out. In group I, 9 items (55%) of error were found out, and were in order of 5 of Student t-test instead of Paired t-test, and 4 of unnecessary statistical analysis. In group II, 16 items (29.1%) of error were found out, and were in order of 22 of Student t-test instead of Paired t-test, 7 of no multiple comparison test after ANOVA, 6 of Student t-test instead of ANOVA, 6 of unnecessary statistical analysis, and 5 of ANOVA instead of Paired t-test. In conclusion, the results noted that statistical analyses were increased, but statistical errors were decreased with time. But authors suggest that researchers should refer to standard statistical texts and seek advice from professional statisticians to avoid the statistical errors.

  • PDF

Gliding-Mobilization이 견관절유착성관절낭염 환자의 관절가동범위에 미치는 영향 (The Effects on the range of motion of joint with Gliding-Mobilization of the patients of adhesive capsulitis of the shoulder)

  • 정병옥;마상렬;김근조;안병헌
    • 대한물리치료과학회지
    • /
    • 제13권4호
    • /
    • pp.27-34
    • /
    • 2006
  • Purpose : The purpose of this study is to prove the increasing range of motion of joint to the patients of adhesive capsulitis of the shoulder applied the gliding-mobilization. Subjects and methods : The subjects are patients of adhesive capsulitis of the shoulder who have limited range of motion due to capsular pattern on the shoulder. The subjects are volunteer patients without a history of neuromuscular problems and randomly distributed into two groups. 15 experimental subjects(4 male, 11 female) received therapy with gliding-mobilization applied on limited shoulder joint and a second group with 15 control subjects(6 male 9 female) was treated by physiological passive range of motion therapy. The data were analyzed with paired t-test to determine striking differences depending on the course of treatment. Result : 1) In the group treated by gliding-mobilization the range of motion in shoulder flexion was increased in accordance to the course of treatment, and paired t-test showed striking differences(p<.05). 2) The range of motion in shoulder extension was increased in accordance to the course of treatment, and paired t-test showed striking differences(p<0.05). 3) The range of motion in shoulder abduction was increased with serise of treatment, and paired t-test showed striking differences(p<0.05). Conclusion : The gliding-mobilization increases the range of motion of the patient of adhesive capsulitis of the shoulder.

  • PDF

Detecting differentially expressed genes from a mixed data set

  • Lee, Sun-Ho;Kim, In-Young;Kim, Sang-Cheol;Rha, Sun-Young;Chung, Hyun-Chel;Kim, Byung-Soo
    • 한국통계학회:학술대회논문집
    • /
    • 한국통계학회 2003년도 추계 학술발표회 논문집
    • /
    • pp.173-177
    • /
    • 2003
  • When we have both a paired data set and two independent data sets, neither a paired t-test nor a two-sample t-test can be used to detect differences between two samples. In order to identify differentially expressed genes in a mixed data set, a new test statistic is proposed.

  • PDF

수준별 영어강좌 운영에 대한 사례연구 (A Case Study on Implementing Graded English Class)

  • 이창훈
    • 공학교육연구
    • /
    • 제16권4호
    • /
    • pp.15-20
    • /
    • 2013
  • The result of the English test for freshmen showed wide difference in the ability of students, which means the graded class is strongly required. This paper describes the case study about the graded English class that was carried out for the freshman. Every freshman must take an English placement test from problems bank and were classified according to the result of the test. In order to resolve the dissatisfaction of the high level students, the statutes of my university for credit were modified. In order to analyze the effect of the graded class, evaluation test using similar problems was carried out at the end of the semester. The effect of the graded class was analyzed by using the paired samples t-test method and there was a meaningful performance improvement at the average score. Additional improvements in the method of classification and credit granted were made by analyzing the results of the evaluation test and survey.

A PERMUTATION APPROACH TO THE BEHRENS-FISHER PROBLEM

  • Proschan, Michael-A.;, Dean-A.
    • Journal of the Korean Statistical Society
    • /
    • 제33권1호
    • /
    • pp.79-97
    • /
    • 2004
  • We propose a permutation approach to the classic Behrens-Fisher problem of comparing two means in the presence of unequal variances. It is motivated by the observation that a paired test is valid whether or not the variances are equal. Rather than using a single arbitrary pairing of the data, we average over all possible pairings. We do this in both a parametric and nonparametric setting. When the sample sizes are equal, the parametric version is equivalent to referral of the unpaired t-statistic to a t-table with half the usual degrees of freedom. The derivation provides an interesting representation of the unpaired t-statistic in terms of all possible pairwise t-statistics. The nonparametric version uses the same idea of considering all different pairings of data from the two groups, but applies it to a permutation test setting. Each pairing gives rise to a permutation distribution obtained by relabeling treatment and control within pairs. The totality of different mean differences across all possible pairings and relabelings forms the null distribution upon which the p-value is based. The conservatism of this procedure diminishes as the disparity in variances increases, disappearing completely when the ratio of the smaller to larger variance approaches 0. The nonparametric procedure behaves increasingly like a paired t-test as the sample sizes increase.