Tag: statistics

Int J Biostat. 2021 Mar 24. doi: 10.1515/ijb-2020-0091. Online ahead of print.

ABSTRACT

The receiver operating-characteristic (ROC) curve is a well-known graphical tool routinely used for evaluating the discriminatory ability of continuous markers, referring to a binary characteristic. The area under the curve (AUC) has been proposed as a summarized accuracy index. Higher values of the marker are usually associated with higher probabilities of having the characteristic under study. However, there are other situations where both, higher and lower marker scores, are associated with a positive result. The generalized ROC (gROC) curve has been proposed as a proper extension of the ROC curve to fit these situations. Of course, the corresponding area under the gROC curve, gAUC, has also been introduced as a global measure of the classification capacity. In this paper, we study in deep the gAUC properties. The weak convergence of its empirical estimator is provided while deriving an explicit and useful expression for the asymptotic variance. We also obtain the expression for the asymptotic covariance of related gAUCs and propose a non-parametric procedure to compare them. The finite-samples behavior is studied through Monte Carlo simulations under different scenarios, presenting a real-world problem in order to illustrate its practical application. The R code functions implementing the procedures are provided as Supplementary Material.

PMID:33761578 | DOI:10.1515/ijb-2020-0091

Gesundheitswesen. 2021 Mar 24. doi: 10.1055/a-1330-7267. Online ahead of print.

ABSTRACT

HINTERGRUND: Das Projekt “Gesunde Südstadt” hat den Schwerpunkt Gesundheitsförderung in der Lebenswelt Kommune. Es wurde im Rahmen des “Präventionsgesetzes” (SGB V §20a) initiiert und zielt ab auf die Verringerung der gesundheitlichen Ungleichheit in der Stadt Nürnberg. Die Maßnahmen der kommunalen Gesundheitsförderung im Handlungsfeld Ernährung wurden durch eine externe multiperspektivische, multimethodische Prozess- und Ergebnisevaluation begleitend untersucht.

METHODEN: 55 Maßnahmenberichte, 8 Interviews mit Teilnehmenden sowie 3 Interviews mit Maßnahmendurchführenden wurden mit qualitativer Inhaltsanalyse ausgewertet. Eine Teilnehmendenbefragung (n=35) mittels Fragebögen wurde quantitativ-statistisch ausgewertet.

ERGEBNISSE: Die Ergebnisse zeigen, dass die Gesundheitsförderungsmaßnahmen durch die Teilnehmenden eine hohe Akzeptanz erfuhren und ein ausgeprägtes Maß an Partizipation ermöglicht wurde. Weiterhin zeigen die Ergebnisse, dass die Maßnahmen die interaktive sowie die funktionale Gesundheitskompetenz förderten. Ein empirisches Pfadmodell für kommunale Gesundheitsförderungsprojekte wurde abgeleitet.

SCHLUSSFOLGERUNG: Die Ergebnisse belegen gesundheitsförderliche Effekte eines verhältnis- und verhaltensbasierten, kommunalen Ansatzes zur Gesundheitsförderung bei Teilnehmenden an Maßnahmen im Handlungsfeld Ernährung. Das Projekt “Gesunde Südstadt” stellt einen systematischen, lebensweltrelevanten und niedrigschwelligen Ansatz der soziallagenbezogenen Gesundheitsförderung im kommunalen Setting dar. Methodische Einschränkungen, wie das Querschnittsdesign der Studie, werden diskutiert.

BACKGROUND AND OBJECTIVES: The Project “Gesunde Südstadt” is focused on community-based health promotion interventions. It was initiated as part of the “Prevention Act” (SGB V §20a) and aims to reduce health inequalities in the city of Nuremberg. The community-based health promotion interventions focussing on nutrition were evaluated with an external multi-perspective, multi-method evaluation approach with a focus both on process and outcome results.

METHODS: 55 reports on activities, 8 interviews with participants and 3 interviews with trainers were coded using qualitative content analysis. Statistical analyses were conducted on a participant survey (n=35).

RESULTS: Results showed that the community-based health promotion interventions were not only widely accepted by the participants but also enabled them to participate in health-related activities. Additionally, health promotion interventions in the community were found to promote interactive and functional health competences. An empirically derived path model for community-based health promotion interventions was statistically tested.

CONCLUSIONS: Results show health promotion effects of community-based nutrition-related health promotion interventions on participants. The project “Gesunde Südstadt” thus represents a systematic, relevant and low-threshold approach to health promotion in a communal setting. Methodological limitations such as the cross-sectional design are discussed.

PMID:33761558 | DOI:10.1055/a-1330-7267

Gesundheitswesen. 2021 Mar 24. doi: 10.1055/a-1388-7203. Online ahead of print.

ABSTRACT

BACKGROUND: There are only limited data on the extent to which children and adolescents with the need of integrative assistance (KiJu-PflEh) are considered for outreach dental care service. Aim The aim of this study was to evaluate accounting data from the Kassenzahnärztliche Bundesvereinigung (KZBV) on the use of dental care by KiJU-PflEh. Material and Methods Based on six specific BEMA items (accounting year 2019), the KZBV performed a filtering of GKV-insured persons (0-17 years). The generated data sets of the study group (KiJu-PflEh) and the control group (all KiJu) were made the UW/H available in anonymized form for further analyses.

RESULTS: The study group comprised 1602 KiJu-PflEh (mean age: 11.6 years). The gender ratio from to was 2:1. 56.0% of the KiJu-PflEh underwent diagnostic dental examination. The use of individual prophylactic (IP) measures was as follows: oral hygiene status assessment – IP1 (47.5%), oral health promotion – IP2 (46.1%), fluoridation of the teeth – IP4 (63.1%), fissure sealing per tooth – IP5 (30.1%). Compared to KiJu, statistically significantly fewer IP-measures were taken and carried out in the study group KiJu-PflEh. (KiJu: 85.7%; KiJu-PflEh: 46.7%).

CONCLUSION: For the first time, it was shown that KiJu-PflEh is inadequately cared for and provided with dental care in comparison to peers in the general population. Increased dental care is urgently recommended as the KiJu-PflEh group has a high risk of caries. Medical information is also necessary to implement targeted prevention measures for all KiJu-PflEh. For this purpose, the introduction of a central database, which enables dental and general medical networking, should be driven forward. Furthermore, there is a need for more research to obtain primary data on the epidemiology of caries in KiJu-PflEh to verify the findings of the present pilot study.

PMID:33761559 | DOI:10.1055/a-1388-7203

Homeopathy. 2021 Mar 24. doi: 10.1055/s-0040-1722232. Online ahead of print.

ABSTRACT

BACKGROUND: Though frequently used in practice, research studies have shown inconclusive benefits of homeopathy in the treatment of warts. We aimed to assess the feasibility of a future definitive trial, with preliminary assessment of differences between effects of individualized homeopathic (IH) medicines and placebos in treatment of cutaneous warts.

METHODS: A double-blind, randomized, placebo-controlled trial (n = 60) was conducted at the dermatology outpatient department of D.N. De Homoeopathic Medical College and Hospital, West Bengal. Patients were randomized to receive either IH (n = 30) or identical-looking placebo (n = 30). Primary outcome measures were numbers and sizes of the warts; secondary outcome was the Dermatology Life Quality Index (DLQI) questionnaire measured at baseline, and every month up to 3 months. Group differences and effect sizes were calculated on the intention-to-treat sample.

RESULTS: Attrition rate was 11.6% (IH, 3; placebo, 4). Intra-group changes were significantly greater (all p < 0.05, Friedman tests) in IH than placebo. Inter-group differences were statistically non-significant (all p > 0.05, Mann-Whitney U tests) with small effect sizes-both in the primary outcomes (number of warts after 3 months: IH median [inter-quartile range; IQR] 1 [1, 3] vs. placebo 1 [1, 2]; p = 0.741; size of warts after 3 months: IH 5.6 mm [2.6, 40.2] vs. placebo 6.3 [0.8, 16.7]; p = 0.515) and in the secondary outcomes (DLQI total after 3 months: IH 4.5 [2, 6.2] vs. placebo 4.5 [2.5, 8]; p = 0.935). Thuja occidentalis (28.3%), Natrum muriaticum (10%) and Sulphur (8.3%) were the most frequently prescribed medicines. No harms, homeopathic aggravations, or serious adverse events were reported.

CONCLUSION: As regards efficacy, the preliminary study was inconclusive, with a statistically non-significant direction of effect favoring homeopathy. The trial succeeded in showing that an adequately powered definitive trial is both feasible and warranted.

TRIAL REGISTRATION: CTRI/2019/10/021659; UTN: U1111-1241-7340.

PMID:33761570 | DOI:10.1055/s-0040-1722232

Diving Hyperb Med. 2021 Mar 31;51(1):53-62. doi: 10.28920/dhm51.1.53-62.

ABSTRACT

INTRODUCTION: This study identified characteristics and diving practices of victims of fatal surface supplied breathing apparatus (SSBA) incidents in Australia from 1965-2019 to determine underlying factors and risks associated with these activities, better educate the diving community and prevent such deaths.

METHODS: A hand search was made of ‘Project Stickybeak’ reports from 1965-2000 and SSBA fatality data were compared to the Australasian Diving Safety Foundation fatality database. The National Coronial Information System was searched to identify SSBA diving deaths for 2001-2019. Extracted data were collated and analysed using descriptive statistics and Poisson Regression. A chain of events analysis was used to determine the likely sequence of events.

RESULTS: There were 84 identified SSBA-related deaths during the study period. Most victims were relatively young, healthy males (median age 33 years). At least 50% of victims were undertaking work-related diving, and 37% were recreational diving. Equipment issues, mainly compressor-related, were the main contributor, identified as a predisposing factor in 48% of incidents and as triggers in 24%.

CONCLUSIONS: Preventable surface-supplied diving deaths still occur in both occupational and recreational diving, often from poor equipment maintenance and oversight. Incorrect configuration of the SSBA and lack of training remain on-going problems in recreational users. These could be addressed by improved education, and, failing this, regulatory oversight. The increase in health-related incidents in older participants may be controlled to some extent by greater medical oversight, especially in recreational and non-certified occupational divers who should be encouraged to undergo regular diving medical assessments.

PMID:33761541 | DOI:10.28920/dhm51.1.53-62

Diving Hyperb Med. 2021 Mar 31;51(1):72-77. doi: 10.28920/dhm51.1.72-77.

ABSTRACT

INTRODUCTION: This paper presents a quantitative and qualitative study exploring patients’ knowledge and experience of hyperbaric oxygen treatment (HBOT).

METHODS: Participants included 29 patients with appropriate indications who were undertaking HBOT at facilities in two different locations: Hobart, Australia, and Plymouth, United Kingdom. Participants completed surveys prior to commencing HBOT, after five sessions, and on completion of HBOT. Semi-structured one-to-one interviews were conducted with each individual on conclusion of their course. Data were analysed using descriptive statistics and interpretive description.

RESULTS: Prior to referral, 15/29 (52%) of participants knew HBOT was used to treat divers, and of these, 9/15 (60%) were familiar with its use for non-divers. Only one third sought additional information about the process between referral for HBOT and attending their medical assessment. Anxiety was a pre-treatment concern amongst participants. However, when re-measured after five sessions and upon completion of the HBOT course, anxiety was reduced. The interview data revealed themes based around the physical, emotional and social aspects of HBOT: (1) anxiety within self; (2) naivety to normalisation; (3) enjoyment being a ‘diver’; and (4) burdens of HBOT.

CONCLUSIONS: Many patients experienced anxiety prior to commencing HBOT but, with support, quickly adjusted to treatment, transitioning from a state of naivety to normalisation in their experience of the hyperbaric chamber. They enjoyed feeling like a ‘diver’ and considered aspects of the burdens of treatment, such as finances or logistics, a minor inconvenience. These results highlight the need for psychosocial support during treatment by identifying gaps in patient preparation for HBOT.

PMID:33761544 | DOI:10.28920/dhm51.1.72-77

Gesundheitswesen. 2021 Mar 24. doi: 10.1055/a-1378-8859. Online ahead of print.

ABSTRACT

AIM OF THE STUDY: Taking into consideration and addressing patients’ psychosocial problems is one of the characteristics of good clinical practice; this applies to IBD-patients as well. Since 2014, such patients have been offered an online questionnaire-based problem assessment linked to care recommendations. The primary aim of our data analysis was to carry out a comparative description of socio-demographic and disease-related characteristics of users of the free service.

METHODOLOGY: For a retrospective data analysis, the online sample (OG) comprising 2156 CD and UC patients was compared with 852 individuals who participated in 2 IBD health services research studies (CG). Besides descriptive statistics, regression and covariance analyses were carried out.

RESULTS: The OG differed from CG in a highly significant and partly clinically relevant way. One in 3 of the OG was younger than 30 years of age (CG: 19%); 45% had completed high school (CG: 36%). In the OG, fewer were in disease remission (OG 34%; CG 59%). Even controlling for these differences, the OG reported more often greater burden in 12 of 17 psychosocial problem areas and expressed a greater need for information on 5 of 9 disease-related topic areas.

CONCLUSION: The internet-based assessment of psychosocial problems is used primarily by younger, better educated, and physically as well as psychosocially more burdened IBD patients with comparatively high information needs. The assessment may help them to actively participate in their care. Our data sheds further light on the peculiarities of internet-based study groups.

PMID:33761557 | DOI:10.1055/a-1378-8859

Phys Med Biol. 2021 Mar 24. doi: 10.1088/1361-6560/abf1b8. Online ahead of print.

ABSTRACT

Respiration-induced motion introduces significant positioning uncertainties in radiotherapy treatments for thoracic sites. Accounting for this motion is a non-trivial task commonly addressed with surrogate-based strategies and latency compensating techniques. This study investigates the potential of a new unified probabilistic framework to predict both future target motion in real-time from a surrogate signal and associated uncertainty A Bayesian approach is developed, based on a Kalman filter theory adapted specifically for surrogate measurements. Breathing motions are collected simultaneously from a lung target, two external surrogates (abdominal and thoracic markers) and an internal surrogate (liver structure) for 9 volunteers during 4 minutes, in which severe breathing changes occur to assess the robustness of the method. A comparison with an artificial non-linear neural network (NN) is performed, although no confidence interval prediction is provided. A static worst-case scenario and a simple static design are investigated. Although the NN can reduce the prediction errors from thoracic surrogate in some cases, the Bayesian framework outperforms in most cases the NN when using the other surrogates: bias on predictions is reduced by 38% and 16% on average when using respectively the liver and the abdomen for the simple scenario, and by respectively 40% and 31% for the worst-case scenario. The standard deviation of residuals is reduced on average by up to 42%. The Bayesian method is also found to be more robust to increasing latencies. The thoracic marker appears to be less reliable to predict the target position, while the liver shows to be a better surrogate. A statistical test confirms the significance of both observations. The proposed framework predicts both the future target position and the associated uncertainty, which can be valuably used to further assist motion management decisions. Further investigation is required to improve the predictions by using an adaptive version of the proposed framework.

PMID:33761479 | DOI:10.1088/1361-6560/abf1b8

Med Princ Pract. 2021 Mar 24. doi: 10.1159/000516067. Online ahead of print.

ABSTRACT

A significant number of studies suggests that coffee consumption reduces cancer risk. This beneficial effect is usually ascribed to the presence of polyphenolic antioxidants and anti- inflammatory agents, including caffeine, cafestol, kahweol and chlorogenic acids. To summarize recent literature on this subject we performed a bibliographic search in PubMed and Embase over the period January 2005 to December 2020 to identify cohort studies and meta-analysis (with data collection ensuring quality of selected reports) that could provide quantitative data on the relationship between coffee consumption and common cancers. The totality of eligible scientific papers support the evidence that coffee intake is inversely associated with hepatocellular cancer risk and to a – slight extent- breast cancer risk among postmenopausal women. As to the association with other organs, including esophagus, pancreas, colorectum, kidneys, bladder, ovaries and prostate, the results are less clear as reports reveal conflicting results or statistically non- significant data. Therefore this overview does not allow broad- based conclusions. Important uncertainties include general study design, inhomogeneous patient sampling, different statistical analysis, (deliberate) misreporting of socio- economic status, education, coffee brewing methods, consumption caffeinated or decaffeinated coffee, smoking habits and alcohol intake. Obviously, more epidemiological research needs to be conducted before solid science- based recommendations can be made with regard to coffee consumption.

PMID:33761499 | DOI:10.1159/000516067

Plast Reconstr Surg. 2021 Mar 19. doi: 10.1097/PRS.0000000000007780. Online ahead of print.

ABSTRACT

BACKGROUND: The accepted “one-size-fits-all” dose strategy for prophylactic enoxaparin may not optimize the medication’s risks and benefits after surgical procedures. The authors hypothesized that weight-based administration might improve the pharmacokinetics of prophylactic enoxaparin when compared to fixed-dose administration.

METHODS: The FIxed or Variable Enoxaparin (FIVE) trial was a randomized, double-blind trial that compared the pharmacokinetic and clinical outcomes of patients assigned randomly to postoperative venous thromboembolism prophylaxis using enoxaparin 40 mg twice daily or enoxaparin 0.5 mg/kg twice daily. Patients were randomized after surgery and received the first enoxaparin dose at 8 hours after surgery. Primary hypotheses were (1) weight-based administration is noninferior to a fixed dose for avoiding underanticoagulation (anti-factor Xa <0.2 IU/ml) and (2) weight-based administration is superior to fixed-dose administration for avoiding overanticoagulation (anti-factor Xa >0.4 IU/ml). Secondary endpoints were 90-day venous thromboembolism and bleeding.

RESULTS: In total, 295 patients were randomized, with 151 assigned to fixed-dose and 144 to weight-based administration of enoxaparin. For avoidance of underanticoagulation, weight-based administration had a greater effectiveness (79.9 percent versus 76.6 percent); the 3.3 percent (95 percent CI, -7.5 to 12.5 percent) greater effectiveness achieved statistically significant noninferiority relative to the a priori specified -12 percent noninferiority margin (p = 0.004). For avoidance of overanticoagulation, weight-based enoxaparin administration was superior to fixed-dose administration (90.6 percent versus 82.2 percent); the 8.4 percent (95 percent CI, 0.1 to 16.6 percent) greater effectiveness showed significant safety superiority (p = 0.046). Ninety-day venous thromboembolism and major bleeding were not different between fixed-dose and weight-based cohorts (0.66 percent versus 0.69 percent, p = 0.98; 3.3 percent versus 4.2 percent, p = 0.72, respectively).

CONCLUSION: Weight-based administration showed superior pharmacokinetics for avoidance of underanticoagulation and overanticoagulation in postoperative patients receiving prophylactic enoxaparin.

CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, I.

PMID:33761517 | DOI:10.1097/PRS.0000000000007780