Tag: statistics

Neurourol Urodyn. 2022 Nov 1. doi: 10.1002/nau.25078. Online ahead of print.

ABSTRACT

INTRODUCTION: Patients with lower urinary tract symptoms (LUTS) can be subcategorized into polyuria, normal or oliguria groups. Polyuria may be caused by pathologies including diabetes mellitus (DM), chronic kidney disease (CKD), diabetes insipidus (DI), or primary polydipsia (PPD). While fluid restriction is appropriate for some, doing so in all may result in serious complications. This study investigates the prevalence of these pathologies in LUTS patients with polyuria.

MATERIALS AND METHODS: Two databases were retrospectively queried for men and women who filled out a lower urinary tract symptom score (LUTSS) questionnaire, 24-h bladder diary (24HBD) and were polyuric (>2.5 L/day). Patients were divided into four groups: poorly controlled DM, DI, an CKD grade 3 and PPD. One-way analysis of variance compared 24HBD and LUTSS questionnaires. Pearson correlation examined LUTSS and bother with 24-h voided volume (24 HVV), maximum voided volume (MVV) and total voids.

RESULTS: Among 814 patients who completed a 24HBD, 176 had polyuria (22%). Of the patients with complete data, 7.8% had poorly-controlled DM, 3.1% had DI, 4.7% had CKD grade 3% and 84.4% had PPD. Amongst the four different sub-groups, significant differences were seen in 24 HVV (p < 0.001), nocturnal urine volume (NUV) (p < 0.001), MVV (p = 0.003), daytime voids (p = 0.05), nocturnal polyuria index (NPi) (p < 0.001) and nocturia index (Ni) (p = 0.002). Significance was also seen between LUTSS and bother subscore (r = 0.68, p < 0.001), LUTSS and total voids (r = 0.29, p = 0.001) and bother sub-score and total voids (r = 0.21, p = 0.019).

CONCLUSIONS: 22% of patients with LUTS were found to have polyuria based on a 24HBD. Within this cohort, four sub-populations were identified as being demonstrating statistically significant differences in 24 HVV, NUV, MVV, daytime voids, NPi and Ni. Identifying the underlying etiology of polyuria should be carried out to safely treat patients with LUTS.

PMID:36317410 | DOI:10.1002/nau.25078

Epidemiol Health. 2022 Oct 24:e2022093. doi: 10.4178/epih.e2022093. Online ahead of print.

ABSTRACT

OBJECTIVES: According to previous findings, stressful life events (SLEs), and its subtypes are associated with depressive symptoms. However, few studies have explored potential models for events and incidental symptoms.

METHODS: The participants (men: 3,966 men; women: 5,709) were recruited from the Cardiovascular and Metabolic Diseases Etiology Research Center. SLEs were measured using a 47-item life experiences survey (LES) with a standardized protocol. Depressive symptoms were assessed using the Beck Depression Inventory II (BDI-II). The joint latent space item response models were performed by sex and age group (under 50 vs. 50+ years).

RESULTS: Among the LESs’ item, death/illness of close relatives, legal/sexual difficulties, family relationships, or social relationships shared latent positions with major depressive symptoms regardless of sex or age. We also observed a sex-specific domain; occupational and family-related items.

CONCLUSION: By projecting LES and BDI-II into the same interaction map in each subgroup, we could specify the association between specific LES and depressive symptoms.

PMID:36317403 | DOI:10.4178/epih.e2022093

Epidemiol Health. 2022 Oct 28:e2022096. doi: 10.4178/epih.e2022096. Online ahead of print.

ABSTRACT

OBJECTIVES: The Korea National Health and Nutrition Examination Survey (KNHANES) is a public health survey that assesses individual health and nutritional status and monitors the prevalence of major chronic diseases. In general, sampling weights are adjusted for unit non-responses and imputation for item non-responses. In this study, we proposed strategies for imputing item non-responses in the KNHANES in order to improve the usefulness of data, to minimize bias, and to increase statistical power.

METHODS: After applying some logical imputation, we adopted two separate imputation methods for each type of variables: unweighted sequential hot-deck imputation for categorical variables and sequential regression imputation for continuous variables. For variance estimation, multiple imputations were applied to the continuous variables. To evaluate the performance of the proposed strategies, we compared marginal distributions of imputed variables and the results multivariate regression analysis for the complete-case data and the expanded data with imputed values, respectively.

RESULTS: When comparing the marginal distributions, most of non-responses were imputed. The multivariable regression coefficients presented similar estimates; however, the standard errors decreased, resulting in a statistically significant P-values. Our evaluation shows that the proposed imputation strategies may cope with precision loss due to missing data, thus enhancing statistical power in the analysis of the KNHANES by providing expanded data with imputed values.

CONCLUSION: The proposed imputation strategy may enhance utility of data by increasing the number of complete-cases in the analysis while distorting the original distribution, thus laying a foundation to cope with the occurrence of item non-response in further surveys.

PMID:36317400 | DOI:10.4178/epih.e2022096

Stat Methods Med Res. 2022 Nov 1:9622802221134172. doi: 10.1177/09622802221134172. Online ahead of print.

ABSTRACT

We propose a flexible and scalable approximate Bayesian inference methodology for the Cox Proportional Hazards model with partial likelihood. The model we consider includes nonlinear covariate effects and correlated survival times. The proposed method is based on nested approximations and adaptive quadrature, and the computational burden of working with the log-partial likelihood is mitigated through automatic differentiation and Laplace approximation. We provide two simulation studies to show the accuracy of the proposed approach, compared with the existing methods. We demonstrate the practical utility of our method and its computational advantages over Markov Chain Monte Carlo methods through the analysis of Kidney infection times, which are paired, and the analysis of Leukemia survival times with a semi-parametric covariate effect and spatial variation.

PMID:36317395 | DOI:10.1177/09622802221134172

Stat Methods Med Res. 2022 Nov 1:9622802221133554. doi: 10.1177/09622802221133554. Online ahead of print.

ABSTRACT

Survival data with multiple outcomes are frequently encountered in biomedical investigations. An illustrative example comes from Alzheimer’s Disease Neuroimaging Initiative study where the cognitively normal subjects may clinically progress to mild cognitive impairment and/or Alzheimer’s disease dementia. Transition time from normal cognition to mild cognitive impairment and that from mild cognitive impairment to Alzheimer’s disease are expected to be correlated within subjects and the dependence is often accommodated by the frailty (random effects). Estimation in the frailty model unavoidably involves multiple integrations which may be intractable and hence leads to severe computational challenges, especially in the presence of high-dimensional covariates. In this paper, we propose efficient minorization-maximization algorithms in the frailty model for survival data with multiple outcomes. The alternating direction method of multipliers is further incorporated for simultaneous variable selection and homogeneity pursuit via regularization and fusion. Extensive simulation studies are conducted to assess the performance of the proposed algorithms. An application to the Alzheimer’s Disease Neuroimaging Initiative data is also provided to illustrate their practical utilities.

PMID:36317365 | DOI:10.1177/09622802221133554

Stat Med. 2022 Nov 1. doi: 10.1002/sim.9599. Online ahead of print.

ABSTRACT

There is a growing interest in current medical research to develop personalized treatments using a molecular-based approach. The broad goal is to implement a more precise and targeted decision-making process, relative to traditional treatments based primarily on clinical diagnoses. Specifically, we consider patients affected by Acute Myeloid Leukemia (AML), an hematological cancer characterized by uncontrolled proliferation of hematopoietic stem cells in the bone marrow. Because AML responds poorly to chemotherapeutic treatments, the development of targeted therapies is essential to improve patients’ prospects. In particular, the dataset we analyze contains the levels of proteins involved in cell cycle regulation and linked to the progression of the disease. We evaluate treatment effects within a causal framework represented by a Directed Acyclic Graph (DAG) model, whose vertices are the protein levels in the network. A major obstacle in implementing the above program is represented by individual heterogeneity. We address this issue through a Dirichlet Process (DP) mixture of Gaussian DAG-models where both the graphical structure as well as the allied model parameters are regarded as uncertain. Our procedure determines a clustering structure of the units reflecting the underlying heterogeneity, and produces subject-specific estimates of causal effects based on Bayesian Model Averaging (BMA). With reference to the AML dataset, we identify different effects of protein regulation among individuals; moreover, our method clusters patients into groups that exhibit only mild similarities with traditional categories based on morphological features.

PMID:36317356 | DOI:10.1002/sim.9599

Bone Joint J. 2022 Nov;104-B(11):1196-1201. doi: 10.1302/0301-620X.104B11.BJJ-2022-0194.R2.

ABSTRACT

AIMS: Although CT is considered the benchmark to measure femoral version, 3D biplanar radiography (hipEOS) has recently emerged as a possible alternative with reduced exposure to ionizing radiation and shorter examination time. The aim of our study was to evaluate femoral stem version in postoperative total hip arthroplasty (THA) patients and compare the accuracy of hipEOS to CT. We hypothesize that there will be no significant difference in calculated femoral stem version measurements between the two imaging methods.

METHODS: In this study, 45 patients who underwent THA between February 2016 and February 2020 and had both a postoperative CT and EOS scan were included for evaluation. A fellowship-trained musculoskeletal radiologist and radiological technician measured femoral version for CT and 3D EOS, respectively. Comparison of values for each imaging modality were assessed for statistical significance.

RESULTS: Comparison of the mean postoperative femoral stem version measurements between CT and 3D hipEOS showed no significant difference (p = 0.862). In addition, the two version measurements were strongly correlated (r = 0.95; p < 0.001), and the mean paired difference in postoperative femoral version for CT scan and 3D biplanar radiography was -0.09° (95% confidence interval -1.09 to 0.91). Only three stem measurements (6.7%) were considered outliers with a > 5° difference.

CONCLUSION: Our study supports the use of low-dose biplanar radiography for the postoperative assessment of femoral stem version after THA, demonstrating high correlation with CT. We found no significant difference for postoperative femoral version when comparing CT to 3D EOS. We believe 3D EOS is a reliable option to measure postoperative femoral version given its advantages of lower radiation dosage and shorter examination time.Cite this article: Bone Joint J 2022;104-B(11):1196-1201.

PMID:36317354 | DOI:10.1302/0301-620X.104B11.BJJ-2022-0194.R2

Bone Joint J. 2022 Nov;104-B(11):1256-1265. doi: 10.1302/0301-620X.104B11.BJJ-2022-0653.R1.

ABSTRACT

AIMS: To determine whether platelet-rich plasma (PRP) injection improves outcomes two years after acute Achilles tendon rupture.

METHODS: A randomized multicentre two-arm parallel-group, participant- and assessor-blinded superiority trial was undertaken. Recruitment commenced on 28 July 2015 and two-year follow-up was completed in 21 October 2019. Participants were 230 adults aged 18 years and over, with acute Achilles tendon rupture managed with non-surgical treatment from 19 UK hospitals. Exclusions were insertion or musculotendinous junction injuries, major leg injury or deformity, diabetes, platelet or haematological disorder, medication with systemic corticosteroids, anticoagulation therapy treatment, and other contraindicating conditions. Participants were randomized via a central online system 1:1 to PRP or placebo injection. The main outcome measure was Achilles Tendon Rupture Score (ATRS) at two years via postal questionnaire. Other outcomes were pain, recovery goal attainment, and quality of life. Analysis was by intention-to-treat.

RESULTS: A total of 230 participants were randomized, 114 to PRP and 116 to placebo. Two-year questionnaires were sent to 216 participants who completed a six-month questionnaire. Overall, 182/216 participants (84%) completed the two-year questionnaire. Participants were aged a mean of 46 years (SD 13.0) and 25% were female (57/230). The majority of participants received the allocated intervention (219/229, 96%). Mean ATRS scores at two years were 82.2 (SD 18.3) in the PRP group (n = 85) and 83.8 (SD 16.0) in the placebo group (n = 92). There was no evidence of a difference in the ATRS at two years (adjusted mean difference -0.752, 95% confidence interval -5.523 to 4.020; p = 0.757) or in other secondary outcomes, and there were no re-ruptures between 24 weeks and two years.

CONCLUSION: PRP injection did not improve patient-reported function or quality of life two years after acute Achilles tendon rupture compared with placebo. The evidence from this study indicates that PRP offers no patient benefit in the longer term for patients with acute Achilles tendon rupture.Cite this article: Bone Joint J 2022;104-B(11):1256-1265.

PMID:36317349 | DOI:10.1302/0301-620X.104B11.BJJ-2022-0653.R1

Bone Joint J. 2022 Nov;104-B(11):1234-1241. doi: 10.1302/0301-620X.104B11.BJJ-2022-0422.R2.

ABSTRACT

AIMS: This study compared patients who underwent arthroscopic repair of large to massive rotator cuff tears (LMRCTs) with isolated incomplete repair of the tear and patients with incomplete repair with biceps tendon augmentation. We aimed to evaluate the additional benefit on clinical outcomes and the capacity to lower the re-tear rate.

METHODS: We retrospectively reviewed 1,115 patients who underwent arthroscopic rotator cuff repair for full-thickness tears between October 2011 and May 2019. From this series, we identified 77 patients (28 male, 49 female) with a mean age of 64.1 years (50 to 80). Patients were classified into groups A (n = 47 incomplete) and B (n = 30 with biceps augmentation) according to the nature of their reconstruction. Clinical scores were checked preoperatively and at six months, one year, and two years postoperatively. In preoperative MRI, we measured the tear size, the degree of fatty infiltration, and muscle volume ratio of the supraspinatus. In postoperative MRI, the integrity of the repaired rotator cuff tendon was assessed using the Sugaya classification. Tendon thickness at the footprint was evaluated on T2-weighted oblique coronal view.

RESULTS: There were no significant differences in the initial preoperative demographic characteristics. In both groups, there were significant improvements in postoperative clinical scores (p < 0.001). However, most clinical outcomes, including range of motion measurements (forward elevation, external rotation, internal rotation, and abduction), showed no differences between the pre- and postoperative values. Comparing the postoperative outcomes of both groups, no further improvement from biceps augmentation was found. Group B, although not reaching statistical significance, had more re-tears than group A (30% vs 15%; p = 0.117).

CONCLUSION: In LMRCTs, biceps augmentation provided no significant improvement of an incomplete repair. Therefore, biceps augmentation is not recommended in the treatment of LMRCTs.Cite this article: Bone Joint J 2022;104-B(11):1234-1241.

PMID:36317346 | DOI:10.1302/0301-620X.104B11.BJJ-2022-0422.R2

Bone Joint J. 2022 Nov;104-B(11):1225-1233. doi: 10.1302/0301-620X.104B11.BJJ-2022-0386.R1.

ABSTRACT

AIMS: The aim of this study was to compare the cost-effectiveness of surgical fixation with Kirschner (K-)wire ersus moulded casting after manipulation of a fracture of the distal radius in an operating theatre setting.

METHODS: An economic evaluation was conducted based on data collected from the Distal Radius Acute Fracture Fixation Trial 2 (DRAFFT2) multicentre randomized controlled trial in the UK. Resource use was collected at three, six, and 12 months post-randomization using trial case report forms and participant-completed questionnaires. Cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY) gained from an NHS and personal social services perspective. Sensitivity analyses were conducted to examine the robustness of cost-effectiveness estimates, and decision uncertainty was handled using confidence ellipses and cost-effectiveness acceptability curves.

RESULTS: In the base case analysis, surgical fixation with K-wire was more expensive (£29.65 (95% confidence interval (CI) -94.85 to 154.15)) and generated lower QALYs (0.007 (95% CI -0.03 to 0.016)) than moulded casting, but this difference was not statistically significant. The probability of K-wire being cost-effective at a £20,000 per QALY cost-effectiveness threshold was 24%. The cost-effectiveness results remained robust in the sensitivity analyses.

CONCLUSION: The findings suggest that surgical fixation with K-wire is unlikely to be a cost-effective alternative to a moulded cast in adults, following manipulation of a fracture of the distal radius in a theatre setting.Cite this article: Bone Joint J 2022;104-B(11):1225-1233.

PMID:36317342 | DOI:10.1302/0301-620X.104B11.BJJ-2022-0386.R1