• Title/Summary/Keyword: multiple linear and non-linear regression

Search Result 173, Processing Time 0.03 seconds

The Relationship between Posttraumatic Stress Disorder and the Quality of Life among the Vietnam War Veterans (베트남전 참전 퇴역 군인에서 외상후스트레스장애와 삶의 질과의 관계)

  • Oum, Se-Joon;Choi, Jin-Hee;Kim, Tae-Yong;Chung, Hae-Gyung;Chung, Moon-Yong;So, Hyung-Seok
    • Korean Journal of Psychosomatic Medicine
    • /
    • v.19 no.2
    • /
    • pp.83-91
    • /
    • 2011
  • Objectives: Posttraumatic stress disorder(PTSD) has devastating effects on multiple aspects of the quality of life(QoL). Therefore, the purpose of this study is to compare the QoL between PTSD group and non-PTSD group, and identify the variables affecting the QoL of the Vietnam War veterans. Methods: We recruited 39 veterans with PTSD and 43 veterans without PTSD, all of whom had deployed to the Vietnam War. We used the Korean version of Mini International Neuropsychiatric Interview-Plus, the Korean version of Clinician-Administered PTSD Scale, Combat Exposure Scale and the Korean version of World Health Organization Quality of Life Assessment Instrument abbreviated version. We used independent samples t-test to identify the differences between PTSD and non-PTSD group in each domains of the quality of life. We also used stepwise multiple linear regression analysis to figure out the variables affecting the QoL of the Vietnam War veterans. Results: In the PTSD group, all domains of the QoL and the QoL total score(p<0.01) were significantly lower than those in the non-PTSD group. In the Vietnam War veterans, PTSD, major depressive disorder and education levels were the variables affecting the QoL. Among these, PTSD uniquely explained the QoL of the overall and general health(${\beta}$=-1.411, $R^2$=0.180), the physical health domain(${\beta}$=-2.806, $R^2$=0.089) and the total score (${\beta}$=-11.479, $R^2$=0.104). Conclusions: These results suggest that among the Vietnam War veterans, the QoL of the PTSD group is significantly lower than that of the non-PTSD group. Among the combat exposed veterans, PTSD may be one of the main reasons that affect the multiple domains of the QoL.

  • PDF

Lifestyle Practice among Malaysian University Students

  • Al-Naggar, Redhwan Ahmed;Bobryshev, Yuri V.;Mohd Noor, Nor Aini Binti
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.3
    • /
    • pp.1895-1903
    • /
    • 2013
  • Background: It is well established that a healthy lifestyle is of benefit in the prevention of diseases such as cancer and promotion of well-being. Therefore, the objective of this study was to determine lifestyle practice and associated factors among university students in Malaysia. Materials and Methods: A cross sectional study was conducted over six months from November 2011 until May 2012 among the students from the Management and Science University. This study was approved by its ethical committee, the students being explained the objective and invited to participate. A consent form was signed by all study participants. Questionnaire was distributed randomly to the students of the five faculties through their lecturers in different faculty. For univariate analysis t-test and ANOVA test were performed. Multiple linear regression used for multivariate analysis using SPSS 13.0. Results: A total number of 1100 students participated with a mean age of $22.1{\pm}2.21$ (SD) years. The majority were 22 years or younger (56.3%), female (54%), Malay (61.5%), single (92.3%), with family monthly income ${\geq}5000$ Ringgit Malaysia (41.2%). Regarding lifestyle, about were 31.6% smokers, 75.6% never drank alcohol and 53.7% never exercised. Multivariate analysis showed that age, sex, race, parent marital status, participant marital status, type of faculty, living status, smoking status, exercise, residency, brushing teeth, fiber intake and avoid fatty food significantly influenced the practice of drinking alcohol among university students (p=0.006, p=0.042, p<0.001, p=0.003, p=0.002, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p=0.003, p<0.001; respectively). It similarly showed that sex, race, parent marital status, participant marital status, monthly family income, exercise, residency, brushing teeth and fiber intake significantly influenced the practice of sun protection (p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p=0.017, p<0.001, p<0.001, p<0.001; respectively) and that age, sex, parent marital status, participant marital status, type of faculty, living status, exercise, taking non-prescribed medication, brushing the teeth, coffee consumption and fiber intake were significantly influenced the practice of fruits consumption (p=0.008, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p=0.002, p<0.001, P<0.001; respectively). Conclusions: This study showed a poor practice of healthy lifestyle among university students. Therefore universities should emphasize a healthy lifestyle in all faculties as a required subject. Socio-demographic characteristics significantly influenced practice and thus should be considered when planning preventive measures among university students. Frequent campaigns and educational seminars are to be encouraged.

Chronic Obstructive Pulmonary Disease Is Not Associated with a Poor Prognosis in COVID-19

  • Kim, Youlim;An, Tai Joon;Park, Yong Bum;Kim, Kyungjoo;Cho, Do Yeon;Rhee, Chin Kook;Yoo, Kwang-Ha
    • Tuberculosis and Respiratory Diseases
    • /
    • v.85 no.1
    • /
    • pp.74-79
    • /
    • 2022
  • Background: The effect of underlying chronic obstructive pulmonary disease (COPD) on coronavirus disease 2019 (COVID-19) during a pandemic is controversial. The purpose of this study was to examine the prognosis of COVID-19 according to the underlying COPD. Methods: COVID-19 patients were assessed using nationwide health insurance data. Comorbidities were evaluated using the modified Charlson Comorbidity Index (mCCI) which excluded COPD from conventional CCI scores. Baseline characteristics were assessed. Univariable and multiple logistic and linear regression analyses were performed to determine effects of variables on clinical outcomes. Ages, sex, mCCI, socioeconomic status, and underlying COPD were selected as variables. Results: COPD patients showed older age (71.3±11.6 years vs. 47.7±19.1 years, p<0.001), higher mCCI (2.6±1.9 vs. 0.8±1.3, p<0.001), and higher mortality (22.9% vs. 3.2%, p<0.001) than non-COPD patients. The intensive care unit admission rate and hospital length of stay were not significantly different between the two groups. All variables were associated with mortality in univariate analysis. However, underlying COPD was not associated with mortality unlike other variables in the adjusted analysis. Older age (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.11-1.14; p<0.001), male sex (OR, 2.29; 95% CI, 1.67-3.12; p<0.001), higher mCCI (OR, 1.30; 95% CI, 1.20-1.41; p<0.001), and medical aid insurance (OR, 1.55; 95% CI, 1.03-2.32; p=0.035) were associated with mortality. Conclusion: Underlying COPD is not associated with a poor prognosis of COVID-19.

Influence of preparation depths on the fracture load of customized zirconia abutments with titanium insert

  • Joo, Han-Sung;Yang, Hong-So;Park, Sang-Won;Kim, Hyun-Seung;Yun, Kwi-Dug;Ji, Min-Kyung;Lim, Hyun-Pil
    • The Journal of Advanced Prosthodontics
    • /
    • v.7 no.3
    • /
    • pp.183-190
    • /
    • 2015
  • PURPOSE. This study evaluated the fracture load of customized zirconia abutments with titanium insert according to preparation depths, with or without 5-year artificial aging. MATERIALS AND METHODS. Thirty-six identical lithium disilicate crowns (IPS e.max press) were fabricated to replace a maxillary right central incisor and cemented to the customized zirconia abutment with titanium insert on a $4.5{\times}10$ mm titanium fixture. Abutments were fabricated with 3 preparation depths (0.5 mm, 0.7 mm, and 0.9 mm). Half of the samples were then processed using thermocycling (temperature: $5-55^{\circ}C$, dwelling time: 120s) and chewing simulation (1,200,000 cycles, 49 N load). All specimens were classified into 6 groups depending on the preparation depth and artificial aging (non-artificial aging groups: N5, N7, N9; artificial aging groups: A5, A7, A9). Static load was applied at 135 degrees to the implant axis in a universal testing machine. Statistical analyses of the results were performed using 1-way ANOVA, 2-way ANOVA, independent t-test and multiple linear regression. RESULTS. The fracture loads were $539.28{\pm}63.11$ N (N5), $406.56{\pm}28.94$ N (N7), $366.66{\pm}30.19$ N (N9), $392.61{\pm}50.57$ N (A5), $317.94{\pm}30.05$ N (A7), and $292.74{\pm}37.15$ N (A9). The fracture load of group N5 was significantly higher than those of group N7 and N9 (P<.017). Consequently, the fracture load of group A5 was also significantly higher than those of group A7 and A9 (P<.05). After artificial aging, the fracture load was significantly decreased in all groups with various preparation depths (P<.05). CONCLUSION. The fracture load of a single anterior implant restored with lithium disilicate crown on zirconia abutment with titanium insert differed depending on the preparation depths. After 5-year artificial aging, the fracture loads of all preparation groups decreased significantly.

Factors to Predict Successful Harvest during Autologous Peripheral Hematopoietic Stem Cell Collection

  • Kim, Mun-Ja;Jin, Soo-He;Lee, Duk-Hee;Park, Dae-Weon;Koh, Sung-Ae;Lee, Kyung-Hee;Hyun, Myung-Soo;Kim, Min-Kyoung
    • Biomedical Science Letters
    • /
    • v.18 no.2
    • /
    • pp.131-138
    • /
    • 2012
  • Autologous peripheral blood stem cell transplantation (PBSCT) has been used as a major treatment strategy for hematological malignancies. The number of CD34 positive cells in the harvested product is a very important factor for achieving successful transplantation. We studied the factors that can predict the number of CD34 positive cells in the harvested product of acute myelocytic leukemia (AML), multiple myeloma (MM) and Non-Hodgkin's lymphoma (NHL) patients after mobilizing them with chemotherapy plus G-CSF. A total of 73 patients (AML 19 patients, MM 28 patients, NHL 26 patients) with hematological malignancies had been mobilized with chemotherapy and granulocyte colony-stimulating growth factor from April, 2000 to February, 2012. Group's characteristics, checkup opinion of pre-peripheral blood on the day of harvest & outcome of PBSC were analyzed and evaluated using SPSS statistics program after grouping patients as below; group 1: CD34 cell counts < $2{\times}10^6/kg$ (n=16); group 2: $2{\times}10^6/kg{\leq}CD34$ cell counts < $6{\times}10^6/kg$ (n=32); group 3: CD34 cell counts ${\geq}6{\times}10^6/kg$ (n=25). We analyzed the clinical characteristics, the peripheral blood (PB) parameters and the number of CD34 positive cells in the PB and their correlation with the yield of CD34 positive cells collected from the mobilized patients. The total number of leukapheresis sessions was 263 (mean: 3.55 session per patient), and the mean number of harvested CD34 positive cells per patient was $7.37{\times}10^6/kg$. The number of CD34 positive cells in product was significantly correlated with the number of platelet and CD34 positive cells in peripheral blood (P<0.05). The number of PB CD34 positive cells was the best significant factor for the quantity of harvested CD34 positive cells on the linear regression analysis (P<0.05). Many factors could influence the mobilization of peripheral blood stem cells. Platelet count and PB CD34 positive cells count were the two variables which remained to be significant in multivariate analysis. Therefore, the number of platelet and CD34 positive cells in peripheral blood on the day of harvest can be used as an accurate predictor for successful peripheral blood stem cell collection.

The Sociological Antecedents of Brand Attachment: A comparison of Broadcasting and Passive Consumption on Social Networking Sites (상표 애착의 사회적 선행변수에 대한 연구)

  • Shin, Jong-Kuk;Park, Min-Sook;Ross, Corey Allen
    • Journal of Digital Convergence
    • /
    • v.14 no.9
    • /
    • pp.159-170
    • /
    • 2016
  • In this study, the authors examine the ways in which social media ultimately affects the attachment of individuals to their favorite brands. Through an analysis of data using multiple linear regression, this study finds that SNS (social networking site) users that post status updates for a wide audience have no bearing on the individual's use of socialization agents. Those who consume social news passively are, however, likely to depend on socialization agents for determining their final purchase decisions. Socialization agents, both personal and non-personal, also play a role in the formation of brand attachment among individuals who depend on these social sources. Based on these results, marketers are encouraged to establish an online footprint of a social nature to formulate brand awareness and to provide a means for users of social media to improve their brand attachments to their favored brands. As this research was conducted exclusively in the predominantly collective culture of South Korea, further studies could attempt to analyze social networking use and socialization agent use via a cross-culture study, particularly one including an individualistic culture.

The Effect of VDT Work on Vision and Eye Symptoms among Workers in a TV Manufacturing Plant (텔레비젼(TV)생산업체 근로자들의 영상단말기(VDT)작업이 시력과 안증상에 미치는 영향)

  • Woo, Kuck-Hyeun;Choi, Gwang-Seo;Jung, Young-Yeon;Han, Gu-Wung;Park, Jung-Han;Lee, Jong-Hyeob
    • Journal of Preventive Medicine and Public Health
    • /
    • v.25 no.3 s.39
    • /
    • pp.247-268
    • /
    • 1992
  • This study was conducted to evaluate the effect of VDT work on eyes and vision among workers in a TV manufacturing plant. The study subjects consisted of 264 screen workers and 74 non-screen workers who were less than 40 years old male and had no history of opthalmic diseases such as corneal opacities, trauma, keratitis, etc and whose visual acuity on pre-employment health examination by Han's test chart was 1.0 or above. The screen workers were divided into two groups by actual time for screen work in a day : Group I, 60 workers, lesser than 4 hours a day and group II, 204 workers, more than 4 hours a day. From July to October 1992 a questionnaire was administered to all the study subjects for the general charateristics and subjective eye symptoms after which the opthalmologic tests such as visual acuity, spherical equivalent, lacrimal function, ocular pressure, slit lamp test, fundoscopy were conducted by one opthalmologist. The proportion of workers whose present visual acuity was decreased more than 0.15 in comparison with that on the pre-employment health examination by Han's test chart was 20.6% in Group II. 15.0% in Group I and 14.9% in non-screen workers. However, the differences in proportion were not statistically significant. The proportion of workers with decreased visual acuity was not associated with the age, working duration, use of magnifying glass and type of shift work (independent variables) in all of the three groups. However, screen workers working under poor illumination had a higher proportion of persons with decreased visual acuity than those working under adequate illumination (P<0.05) . The proportion of workers whose near vision was decreased was 27.5% in Group II, 18.3% in Group I, and 28.4% in non-screen workers and these differences in proportion were not statistically significant. Changes of near vision were not associated with 4 independent variables in all of the three groups. Six out of seven subjective eye symptoms except tearing were more common in Group I than in non-screen workers and more common in Group II than in Group I (P<0.01). Mean of the total scores for seven subjective symptoms of each worker(2 points for always, 1 point for sometimes, 0 point for never) was not significantly different between workers with decreased visual acuity and workers with no vision change. However, mean of the total scores for Group II was higher than those for the Group I and non-screen workers (P<0.01). Total eye symptom scores were significantly correlated with the grade of screen work, use of magnifying glass, and type of shift work. There was no independent variable which was correlated with the difference in visual acuity between the pre-employment health examination and the present state, the difference between far and near visions, lacrimal function, ocular pressure, and spherical equivalent. Multiple linear regression analysis for the subjective eye symptom scores revealed a positive linear relationship with actual time for screen work and shift work(P<0.01). In this study it was not observed that the VDT work decreased visual acuity but it induces subjective eye symptoms such as eye fatigue, blurred vision, ocular discomfort, etc. Maintenance of adequate illumination in the work place and control of excessive VDT work are recommended to prevent such eye symptoms.

  • PDF

Correlation between menton deviation and dental compensation in facial asymmetry using cone-beam CT (Cone-beam CT를 이용한 안면비대칭자에서 이부편위에 따른 치성보상의 양상분석)

  • Park, Soo-Byung;Park, Jeong-Heuy;Jung, Yun-Hoa;Jo, Bong-Hye;Kim, Yong-Il
    • The korean journal of orthodontics
    • /
    • v.39 no.5
    • /
    • pp.300-309
    • /
    • 2009
  • Objective: The purpose of this study was to evaluate the correlation between menton deviation and dental compensation in facial asymmetry. Methods: Tooth axis and distance of first molar and canine to the reference plane were investigated by cone-beam computerized tomography. The subjects consisted of 50 patients with asymmetric mandibles (male 21, female 29, mean age 24.3 years). Control groups were also assessed (male 11, female 9, mean age 25.6 years). Nine measurements (5 linear measurements and 4 angular measurements) were measured in order to evaluate the correlation between menton deviation and the linear and angular difference of first molar and canine in the deviated and none-deviated sides using the defined MPR images. The differences between deviated and non-deviated side, according to menton deviation, were statistically analyzed using stepwise multiple regression analysis. Results: From the result, Menton deviation was negatively correlated with mandibular first molar's angular measurement (${\Delta\angle}LM6$-Mn plane (dev.-ndev.)) and positively with maxillary fist molar's angular measurement (${\Delta\angle}UM6$-FH plane (dev.-ndev.)) (p < 0.01). Two angular measurements (${\Delta\angle}LM6$-Mn plane (dev.-ndev.), ${\Delta\angle}UM6$-FH plane (dev.-ndev.)) explained the variability in menton deviation with a significant $r^2$ value of 0.589. Conclusions: This study suggests that the tooth axis of upper and lower first molars leans towards the deviated side of Menton when there is mandibular asymmetry with Menton deviation.

The Effect of Insomnia Severity on Daytime Sleepiness in Obstructive Sleep Apnea Syndrome (불면증 정도가 폐쇄성 수면무호흡 증후군에서의 주간졸림 정도에 끼치는 영향)

  • Nam, Ji-Won;Shin, Byoung-Hak;Shin, Hyeon-Sil;Park, Minji
    • Sleep Medicine and Psychophysiology
    • /
    • v.22 no.1
    • /
    • pp.11-19
    • /
    • 2015
  • Objectives: Whether daytime sleepiness is proportional to the severity of sleep apnea in obstructive sleep apnea syndrome (OSAS) is controversial. In this study we investigated how insomnia severity affects the association between daytime sleepiness and sleep apnea severity in OSAS. Methods: The present study included 235 male subjects who were diagnosed with OSAS based on clinical history and nocturnal polysomnography. Pearson's correlation analysis was conducted among sleep and mood-related self-reported data, polysomnographic data and demographic data of all subjects. Based on Pittsburgh Sleep Quality Index (PSQI), the subjects were divided into 2 groups; group A (n = 75; $PSQI{\leq}5$) and group B (n = 160; PSQI > 5). Partial correlation analysis was performed between the Epworth Sleepiness Scale (ESS) and other data in both groups. Multiple linear regression analysis was conducted to investigate the factors which affected the ESS in group A. Results: Pearson's correlation analysis showed weak or non-existent correlations between ESS and apnea severity data such as apnea-hypopnea index (AHI) (r = 0.148, p = 0.023), apnea index (AI) (r = 0.137, p = 0.036), hypopnea index (HI) (r = 0.058, p = 0.377), oxygen desaturation index (ODI) (r = 0.149, p = 0.022) and arousal total index (ATI) (r = 0.129, p = 0.048). Positive correlations between ESS and apnea severity data such as AHI ($r_p=0.313$, p = 0.008), AI ($r_p=0.339$, p = 0.004), ODI ($r_p=0.289$, p = 0.015) and ATI ($r_p=0.256$, p = 0.031) were observed only in group A. Multiple regression analysis showed that AI (t = 2.996, p = 0.004) and BAI (t = 2.721, p = 0.008) were associated with ESS in group A. Conclusion: The correlation between daytime sleepiness and sleep apnea severity was shown only in group A. This result suggests that associations between daytime sleepiness in OSAS and sleep apnea severity will become prominent when controlling for insomnia-related variables.

Correlational Analysis of Supine Position Time and Sleep-related Variables in Obstructive Sleep Apnea Syndrome (폐쇄성 수면무호흡 증후군에서 앙와위 자세시간과 수면관련변인 간 상관관계 분석)

  • Kim, Si Young;Park, Doo-Heum;Yu, Jaehak;Ryu, Seung-Ho;Ha, Ji-Hyeon
    • Sleep Medicine and Psychophysiology
    • /
    • v.24 no.1
    • /
    • pp.32-37
    • /
    • 2017
  • Objectives: A supine sleep position increases sleep apneas compared to non-supine positions in obstructive sleep apnea syndrome (OSAS). However, supine position time (SPT) is not highly associated with apnea-hypopnea index (AHI) in OSAS. We evaluated the correlation among sleep-related variables and SPT in OSAS. Methods: A total of 365 men with OSAS were enrolled in this study. We analyzed how SPT was correlated with demographic data, sleep structure-related variables, OSAS-related variables and heart rate variability (HRV). Multiple linear regression analysis was conducted to investigate the factors that affected SPT. Results: SPT had the most significant correlation with total sleep time (TST ; r = 0.443, p < 0.001), followed by sleep efficiency (SE ; r = 0.300, p < 0.001). Snoring time (r = 0.238, p < 0.001), time at < 90% SpO2 (r = 0.188, p < 0.001), apnea-hypopnea index (AHI ; r = 0.180, p = 0.001) and oxygen desaturation index (ODI ; r = 0.149, p = 0.004) were significantly correlated with SPT. Multiple regression analysis revealed that TST (t = 7.781, p < 0.001), snoring time (t = 3.794, p < 0.001), AHI (t = 3.768, p < 0.001) and NN50 count (t = 1.993, p = 0.047) were associated with SPT. Conclusion: SPT was more highly associated with sleep structure-related parameters than OSAS-related variables. SPT was correlated with TST, SE, AHI, snoring time and NN50 count. This suggests that SPT is likely to be determined by sleep structure, HRV and the severity of OSAS.