Categories
Nevin Manimala Statistics

Sample size requirements are not being considered in studies developing prediction models for binary outcomes: a systematic review

BMC Med Res Methodol. 2023 Aug 19;23(1):188. doi: 10.1186/s12874-023-02008-1.

ABSTRACT

BACKGROUND: Having an appropriate sample size is important when developing a clinical prediction model. We aimed to review how sample size is considered in studies developing a prediction model for a binary outcome.

METHODS: We searched PubMed for studies published between 01/07/2020 and 30/07/2020 and reviewed the sample size calculations used to develop the prediction models. Using the available information, we calculated the minimum sample size that would be needed to estimate overall risk and minimise overfitting in each study and summarised the difference between the calculated and used sample size.

RESULTS: A total of 119 studies were included, of which nine studies provided sample size justification (8%). The recommended minimum sample size could be calculated for 94 studies: 73% (95% CI: 63-82%) used sample sizes lower than required to estimate overall risk and minimise overfitting including 26% studies that used sample sizes lower than required to estimate overall risk only. A similar number of studies did not meet the ≥ 10EPV criteria (75%, 95% CI: 66-84%). The median deficit of the number of events used to develop a model was 75 [IQR: 234 lower to 7 higher]) which reduced to 63 if the total available data (before any data splitting) was used [IQR:225 lower to 7 higher]. Studies that met the minimum required sample size had a median c-statistic of 0.84 (IQR:0.80 to 0.9) and studies where the minimum sample size was not met had a median c-statistic of 0.83 (IQR: 0.75 to 0.9). Studies that met the ≥ 10 EPP criteria had a median c-statistic of 0.80 (IQR: 0.73 to 0.84).

CONCLUSIONS: Prediction models are often developed with no sample size calculation, as a consequence many are too small to precisely estimate the overall risk. We encourage researchers to justify, perform and report sample size calculations when developing a prediction model.

PMID:37598153 | DOI:10.1186/s12874-023-02008-1

Categories
Nevin Manimala Statistics

In Vitro evaluation of the effects of whitening toothpastes on the color and surface roughness of different composite resin materials

BMC Oral Health. 2023 Aug 19;23(1):580. doi: 10.1186/s12903-023-03277-4.

ABSTRACT

BACKGROUND: The aim of this study was to evaluate the effects of traditional and whitening toothpastes on the color and surface roughness of different composite resin materials.

METHODS: Eighty disc-shaped samples were prepared for each of the following composite resins: nano-hybrid (Filtek Ultimate Universal; 3 M/ESPE, Saint Paul, USA), micro-hybrid (Charisma Smart; Kulzer, Hanau, Germany) and supra-nano-filled (Omnichroma; Tokuyama, Tokyo, Japan). Each composite-resin sample was randomly divided into the following four subgroups (n = 20 per group): Group 1, control; Group 2, traditional toothpaste (Colgate Total 12; Colgate Palmolive, New York, USA); Group 3, peroxide-based toothpaste (Colgate Optic White; Colgate-Palmolive, New York, USA); and Group 4, blue covarine-based toothpaste (Meridol Gentle White; CP-GABA, Hamburg, Germany). The samples for the toothpaste subgroups were immersed in a coffee solution for 10 min and washed twice a day before each brushing cycle. The specimens were brushed for 30 days. Color analyses were performed using a spectrophotometer (SpectroShade Micro, MHT, Italy). Surface roughness analyses were conducted using a profilometer (Surftest SJ-210 Mitutoyo, Tokyo, Japon). The color and surface roughness analyses were performed at baseline and 1, 7 and 30 days after each treatment. Furthermore, surface topography analysis was performed using Scanning Electron Microscopy (FEG 250-FeiQuanta, the Netherlands). The data were analysed with a three-way robust ANOVA and Bonferroni post-hoc correction (p < 0.05).

RESULTS: The smallest color change was observed for the micro-hybrid composite resin, and the greatest color change was observed for the nano-hybrid composite resin. Based on the tested composite resin samples, the greatest color change was obtained after using blue covarine-based toothpaste, while the smallest color change was observed after using peroxide-based toothpaste. Moreover, the supra-nano-filled composite resin samples exhibited the lowest roughness values (robust ANOVA test, p < 0.001). There was no statistically significant difference between the mean values of roughness for the composite, group and time interaction (p = 0.937).

CONCLUSION: Charisma Smart composite resin exhibited significantly lower staining than all the other composite resins tested after using all toothpastes included in the study. Further laboratory and clinical studies are needed to fully understand the long-term effectiveness of whitening toothpaste on composite resin materials.

PMID:37598143 | DOI:10.1186/s12903-023-03277-4

Categories
Nevin Manimala Statistics

Societal costs of personality disorders among treatment-seeking patients in Norway: the relative contribution of specific DSM-5 categories

Eur Arch Psychiatry Clin Neurosci. 2023 Aug 19. doi: 10.1007/s00406-023-01655-1. Online ahead of print.

ABSTRACT

Personality disorders (PDs) are associated with high levels of societal costs, regardless of whether a single PD or a broad range of PDs have been studied. However, research on the relative contribution of specific PD-types on societal costs is limited. The aim of this study was to explore the possible contributions of the individual DSM-5 categories of PDs on the level of societal costs and its components (health service costs and productivity loss), while controlling for the impact of comorbid mental health and substance use disorders on these outcomes. Participants (n = 798) were retrieved from the quality register of the Norwegian Network for Personality Disorders-a collaboration of PD-treatment units within specialist mental health services. The patients were referred to treatment in the time-period 2017-2020. Costs were assessed using a structured interview covering the 6-month period prior to assessment. Diagnoses were determined by semi-structured diagnostic interviews (SCID-5-PD and M.I.N.I.). Statistics included multiple regression analyses. The main result was that no specific PD had a unique contribution to the high level of societal costs generally found among treatment-seeking patients with PDs. Borderline PD (BPD) was the only PD with significantly higher health service costs than the other PDs, while BPD, avoidant PD, and unspecified PD were independently associated with enhanced productivity loss. The differential cost-effects of specific PDs on the cost components were small. Several comorbid mental health and substance use disorders were significant contributors to costs, irrespective of PD status. The results underscore the importance of developing and implementing effective treatments for a broader range of PDs, to reduce the high levels of societal costs associated with all PDs.

PMID:37598131 | DOI:10.1007/s00406-023-01655-1

Categories
Nevin Manimala Statistics

Assessment of particulate matter exposure on ambient air and its impact on workers at two granite quarry mines at Njuli, Southern Malawi

Environ Monit Assess. 2023 Aug 19;195(9):1069. doi: 10.1007/s10661-023-11708-6.

ABSTRACT

Quarrying activities are among the significant sources of pollution caused by particulate matter (PM) in ambient air. Besides affecting the environment, PM exposure is one of the leading causes of respiratory illnesses worldwide. The current study, unique to Malawi, aimed to understand the impact of particulate matter on ambient air and the possible effects on workers’ health at Njuli in Blantyre and Chiradzulu districts. The study measured concentrations of particulate matter in ambient air, conducted a chemical analysis of fallen dust, and surveyed respiratory symptoms. Results showed higher exposures to particulate matter at a Terrastone mine (126 µg/m3 highest exposure) than a Mota Engil mine (83 µg/m3 highest exposure), attributed to poor management practices at Terrastone mine. Higher PM readings (0-85.98 µg/m3) were observed for sites located downwind of the mines than sites located upwind (0-59 µg/m3), demonstrating the impact of quarrying operations at the mines; differences were, however, not statistically significant (P 0.165, Terrastone, P 0.678 Mota Engil). The observed amount of PM in ambient air was consistent with the scale of quarrying and processing operations at both mines, 0-56.2 µg/m3 in pre-operational phases, 0-126.1 µg/m3 during operations, and 0-56 µg/m3 after closure of operations; differences were statistically significant only at Terrastone mine P 0.003. The impact of season variation was observed following lower PM readings recorded during the rainy season than those obtained during the dry season at both mines. Analysis of health symptoms revealed that a higher proportion of workers at the Terrastone mine experienced respiratory symptoms compared to the Mota Engil mine.

PMID:37598112 | DOI:10.1007/s10661-023-11708-6

Categories
Nevin Manimala Statistics

Developing an artificial intelligence-based headache diagnostic model from a clinic patients’ dataset

Headache. 2023 Aug 19. doi: 10.1111/head.14611. Online ahead of print.

ABSTRACT

OBJECTIVE: We developed an artificial intelligence (AI)-based headache diagnosis model using a large questionnaire database in a headache-specializing clinic.

BACKGROUND: Misdiagnosis of headache disorders is a serious issue and AI-based headache diagnosis models are scarce.

METHODS: We developed an AI-based headache diagnosis model and conducted internal validation based on a retrospective investigation of 6058 patients (4240 training dataset for model development and 1818 test dataset for internal validation) diagnosed by a headache specialist. The ground truth was the diagnosis by the headache specialist. The diagnostic performance of the AI model was evaluated.

RESULTS: The dataset included 4829/6058 (79.7%) patients with migraine, 834/6058 (13.8%) with tension-type headache, 78/6058 (1.3%) with trigeminal autonomic cephalalgias, 38/6058 (0.6%) with other primary headache disorders, and 279/6058 (4.6%) with other headaches. The mean (standard deviation) age was 34.7 (14.5) years, and 3986/6058 (65.8%) were female. The model’s micro-average accuracy, sensitivity (recall), specificity, precision, and F-values for the test dataset were 93.7%, 84.2%, 84.2%, 96.1%, and 84.2%, respectively. The diagnostic performance for migraine was high, with a sensitivity of 88.8% and c-statistics of 0.89 (95% confidence interval 0.87-0.91).

CONCLUSIONS: Our AI model demonstrated high diagnostic performance for migraine. If secondary headaches can be ruled out, the model can be a powerful tool for diagnosing migraine; however, further data collection and external validation are required to strengthen the performance, ensure the generalizability in other outpatients, and demonstrate its utility in real-world settings.

PMID:37596885 | DOI:10.1111/head.14611

Categories
Nevin Manimala Statistics

Telomere length and its association with systemic lupus erythematosus in an Asian population: A Mendelian randomization study

Lupus. 2023 Aug 19:9612033231195953. doi: 10.1177/09612033231195953. Online ahead of print.

ABSTRACT

OBJECTIVES: To investigate whether shorter telomere length is a causal risk factor for systemic lupus erythematosus (SLE) in the Asian population.

METHODS: We applied the two-sample Mendelian randomization (MR) method to the pooled statistics from a genome-wide association study (GWAS) of 6,707 SLE cases and 16,047 controls. We selected nine single-nucleotide polymorphisms (SNPs) with genome-wide significance as instrumental variables for telomere length. The main analysis was carried out by the random-effects inverse-variance weighted (IVW) method. Horizontal pleiotropy was evaluated by the intercept of MR-Egger regression.

RESULTS: A potentially causal relationship between longer genetically predicted telomere length and increased risk of systemic lupus erythematosus (OR = 1.72, 95%CI: 1.21, 2.46, p = 0.01) was observed. The MR-Egger regression demonstrated an intercept proximal to zero (intercept = 0.017, p = 0.69), which does not provide evidence of the presence of horizontal pleiotropy.

CONCLUSIONS: Our findings provided evidence supporting a potential causal relationship between longer telomere length and increased risk of systemic lupus erythematosus.

PMID:37596879 | DOI:10.1177/09612033231195953

Categories
Nevin Manimala Statistics

Reinke’s Edema: Cold Steel Versus Radiofrequency Coblation

Ear Nose Throat J. 2023 Aug 19:1455613231194131. doi: 10.1177/01455613231194131. Online ahead of print.

ABSTRACT

OBJECTIVE: This study compared the effects of radiofrequency (RF) coblation and cold steel (CS) surgery for the treatment of Reinke’s edema (RE).

METHODS: A retrospective analysis was conducted on 61 patients with RE, with 33 (54.1%) in the CS surgery group and 28 (45.9%) in the RF coblation group. The primary endpoints were the bilateral operation time and dyspnea severity, assessed preoperatively and at 1 and 3 months postoperatively. Secondary endpoints included subjective and objective vocal assessments, laryngovideostroboscopy (LVS) images, and Voice Handicap Index-10 (VHI-10) scores obtained before and at 1 and 3 months postoperatively.

RESULTS: The average bilateral operation time was significantly shorter in the RF coblation group (24.2 ± 3.9 min) compared to the CS group (38.4 ± 5.2 min) (P = .041). All patients experienced a decrease in their Dyspnea Severity Index (DSI) scores postoperatively, with no significant differences observed between the two groups at any time point. However, improvements in the grade of hoarseness, roughness, and asthenia were significantly greater in the RF coblation group than in the CS group (P < .001). There were no statistically significant differences in breathiness and strain between the two groups. The average VHI-10 score significantly decreased from preoperative values in both groups (P < .001), with no significant differences observed between the two groups at any time point.

CONCLUSIONS: The RF coblation procedure is a reliable and safe method for RE surgery, offering an effective treatment choice for RE.

PMID:37596878 | DOI:10.1177/01455613231194131

Categories
Nevin Manimala Statistics

Feasibility of Multiparametric Perfusion Assessment in Diabetic Foot Ulcer Using Intravoxel Incoherent Motion and Blood Oxygenation-Level Dependent MRI

J Magn Reson Imaging. 2023 Aug 19. doi: 10.1002/jmri.28955. Online ahead of print.

ABSTRACT

BACKGROUND: Patients with type-2 diabetes (T2DM) are at increased risk of developing diabetic foot ulcers (DFU) and experiencing impaired wound healing related to underlying microvascular disease.

PURPOSE: To evaluate the sensitivity of intra-voxel incoherent motion (IVIM) and blood oxygen level dependent (BOLD) MRI to microvascular changes in patients with DFUs.

STUDY TYPE: Case-control.

POPULATION: 20 volunteers who were age and body mass index matched, including T2DM patients with DFUs (N = 10, mean age = 57.5 years), T2DM patients with controlled glycemia and without DFUs (DC, N = 5, mean age = 57.4 years) and healthy controls (HC, N = 5, mean age = 52.8 years).

FIELD STRENGTH/SEQUENCE: 3T/multi-b-value IVIM and dynamic BOLD.

ASSESSMENT: Resting IVIM parameters were obtained using a multi-b-value diffusion-weighted imaging sequence and two IVIM models were fit to obtain diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f) and microvascular volume fraction (MVF) parameters. Microvascular reactivity was evaluated by inducing an ischemic state in the foot with a blood pressure cuff during dynamic BOLD imaging. Perfusion indices were assessed in two regions of the foot: the medial plantar (MP) and lateral plantar (LP) regions.

STATISTICAL TESTS: Effect sizes of group mean differences were assessed using Hedge’s g adjusted for small sample sizes.

RESULTS: DFU participants exhibited elevated D*, f, and MVF values in both regions (g ≥ 1.10) and increased D (g = 1.07) in the MP region compared to DC participants. DC participants showed reduced f and MVF compared to HC participants in the MP region (g ≥ 1.06). Finally, the DFU group showed reduced tolerance for ischemia in the LP region (g = -1.51) and blunted reperfusion response in both regions (g < -2.32) compared to the DC group during the cuff-occlusion challenge.

DATA CONCLUSION: The combined use of IVIM and BOLD MRI shows promise in differentiating perfusion abnormalities in the feet of diabetic patients and suggests hyperperfusion in DFU patients.

LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 1.

PMID:37596872 | DOI:10.1002/jmri.28955

Categories
Nevin Manimala Statistics

Seizure control in women with epilepsy undergoing assisted reproductive technology

Epilepsia. 2023 Aug 19. doi: 10.1111/epi.17748. Online ahead of print.

ABSTRACT

The objective of this study was to determine seizure control in women with epilepsy (WWE) undergoing assisted reproductive technology (ART). Through retrospective chart review, WWE undergoing ART were identified. Demographics and details regarding epilepsy type, seizure control, and ART procedures were extracted. Seizure frequency prior to and during ART were compared. We identified 12 WWE, who underwent 29 embryo transfers, resulting in 16 pregnancies and 10 live births. Nine women were seizure-free at least two years before fertility treatment, including three with resolved epilepsy. Seven were on antiseizure medications (ASMs) throughout fertility treatment and pregnancy, with only one on polytherapy. Eleven (all with controlled epilepsy or epilepsy in remission) remained seizure free throughout fertility treatment. One woman with drug-resistant epilepsy continued to have seizures throughout fertility treatment and pregnancy without an exacerbation of seizure frequency. There was no increased seizure frequency associated with fertility treatment and subsequent pregnancy in this small series of WWE. Although this study was statistically underpowered, our results provide some preliminary evidence that ART might not pose a threat to seizure control, but larger, confirmatory studies are necessary.

PMID:37596834 | DOI:10.1111/epi.17748

Categories
Nevin Manimala Statistics

Covid lockdowns and hospitalisations for oro-facial trauma among children in Australia and the United Kingdom

Dent Traumatol. 2023 Aug 19. doi: 10.1111/edt.12877. Online ahead of print.

ABSTRACT

BACKGROUND/AIM: This retrospective study investigated the effect of lockdowns for Covid-19 on the rates of oro-facial trauma hospitalisations in children in Australia and the United Kingdom (UK).

MATERIALS AND METHODS: Hospitalisation data for children up to 19 years old for oro-facial trauma injuries (according to ICD-10-AM principal diagnosis codes) over 5 years were collected for Australian and UK children. The age-standard rate (ASR) for each age group was calculated per 100,000 population.

RESULTS: In the younger Australian children, there was no statistically significant change in the ASR of oro-facial trauma hospitalisations during the ‘Covid year’, compared to the average rate over the 3 years preceding. However, there was a significant decrease in the ASR of oro-facial trauma hospitalisations during the ‘Covid year’ in older Australian children (aged 10-19), and for all UK children, except for infants under one-year-old.

CONCLUSIONS: Reduction of the ASR of hospitalisations due to oro-facial trauma during the ‘Covid year’, and the implementation of lockdown measures in the two countries provides further evidence of the impact of physical activities and travel as contributing factors to oro-facial injuries in children. In addition to its role in reducing the spread of virus infections during the pandemic, the lockdown measures also resulted in a simultaneous decrease in trauma injuries.

PMID:37596827 | DOI:10.1111/edt.12877