Nevin Manimala

Med Decis Making. 2025 Feb 18:272989X251314010. doi: 10.1177/0272989X251314010. Online ahead of print.

ABSTRACT

BACKGROUND: The purpose of external validation of a risk prediction model is to evaluate its performance before recommending it for use in a new population. Sample size calculations for such validation studies are currently based on classical inferential statistics around metrics of discrimination, calibration, and net benefit (NB). For NB as a measure of clinical utility, the relevance of inferential statistics is doubtful. Value-of-information methodology enables quantifying the value of collecting validation data in terms of expected gain in clinical utility.

METHODS: We define the validation expected value of sample information (EVSI) as the expected gain in NB by procuring a validation sample of a given size. We propose 3 algorithms for EVSI computation and compare their face validity and computation time in simulation studies. In a case study, we use the non-US subset of a clinical trial to create a risk prediction model for short-term mortality after myocardial infarction and calculate validation EVSI at a range of sample sizes for the US population.

RESULTS: Computation methods generated similar EVSI values in simulation studies, although they differed in numerical accuracy and computation times. At 2% risk threshold, procuring 1,000 observations for external validation, had an EVSI of 0.00101 in true-positive units or 0.04938 in false-positive units. Scaled by heart attack incidence in the United States, the population EVSI was 806 in true positives gained, or 39,500 in false positives averted, annually. Validation studies with >4,000 observations had diminishing returns, as the EVSIs were approaching their maximum possible value.

CONCLUSION: Value-of-information methodology quantifies the return on investment from conducting an external validation study and can provide a value-based perspective when designing such studies.

HIGHLIGHTS: In external validation studies of risk prediction models, the finite size of the validation sample leads to uncertain conclusions about the performance of the model. This uncertainty has hitherto been approached from a classical inferential perspective (e.g., confidence interval around the c-statistic).Correspondingly, sample size calculations for validation studies have been based on classical inferential statistics. For measures of clinical utility such as net benefit, the relevance of this approach is doubtful.This article defines the expected value of sample information (EVSI) for model validation and suggests algorithms for its computation. Validation EVSI quantifies the return on investment from conducting a validation study.Value-based approaches rooted in decision theory can complement contemporary study design and sample size calculation methods in predictive analytics.

PMID:39963746 | DOI:10.1177/0272989X251314010

Acta Medica (Hradec Kralove). 2024;67(3):87-90. doi: 10.14712/18059694.2025.3.

ABSTRACT

INTRODUCTION: Time series analysis is used by statisticians to make predictions from time-ordered data. This is crucial for planning for the future. The inclusion of little-known forecasting function in Excel™ has brought this type of analysis within the ability of less mathematically sophisticated individuals, including doctors. There are two main models for time series analysis: ARIMA (Autoregressive Integrated Moving Average) and exponential smoothing. This paper will demonstrate how the ubiquitous Excel facilitates a little-known sophisticated forecasting technique that employs the latter and presents a facilitating spreadsheet.

METHODS: Excel’s FORECAST.ETS function was invoked with supporting macros.

RESULTS: A bespoke spreadsheet was created that would prompt for data to be pasted in columns A and B, formatted as a valid date in A and data in B. After error trapping and a horizon date, the FORECAST.ETS function calculates forecasts with 95% CI and a line graph. The FORECAST.ETS.CONFINT was also invoked using a macro to obtain a 95, 96, 97, 98 and 99% confidence intervals table.

DISCUSSION: Forecasting is vital in all fields, including the medical field, for innumerable reasons. Statisticians are capable of far more sophisticated time series analyses and techniques and may use multiple techniques that are beyond the competence of ordinary clinicians. However, the sophisticated Excel tool described in this paper allows simple forecasting by anyone with some knowledge of this ubiquitous software. It is hoped that the spreadsheet included with this paper helps to encourage colleagues to engage with this simple-to-use Excel function.

PMID:39963736 | DOI:10.14712/18059694.2025.3

Acta Medica (Hradec Kralove). 2024;67(3):73-78. doi: 10.14712/18059694.2025.1.

ABSTRACT

BACKGROUND: During otosclerosis surgery, operative trauma can lead to decreased bone conduction.

AIMS: The study aims to observe the bone conduction changes after otosclerosis operations and analyse possible factors affecting the postoperative decrease in bone conduction.

MATERIAL AND METHODS: Authors retrospectively processed the data of 109 patients and evaluated pure tone audiometry before surgery and consequently 2 days, 1 month and 1 year after surgery.

RESULTS: We noted a deterioration of bone conduction >5 dB on the second postoperative day in 28% (30/109) of patients, which persisted one year after the surgery in 9% (10/109) cases. Analysis of individual factors affecting bone conduction loss revealed a higher risk of permanent loss of bone conduction in patients with early postoperative loss in higher frequencies, in older patients and patients with a preoperative threshold of bone conduction >20 dB. Revision surgery was not a statistically significant factor.

CONCLUSION AND SIGNIFICANCE: The bone conduction decrease after otosclerosis surgery is usually temporary. The recovery of bone conduction is influenced by the age of patients and the level of bone conduction before the surgery. The early postoperative decrease of bone conduction in higher frequencies is a negative predictive factor for permanent hearing loss.

PMID:39963734 | DOI:10.14712/18059694.2025.1

J Pediatr Gastroenterol Nutr. 2025 Feb 18. doi: 10.1002/jpn3.70018. Online ahead of print.

ABSTRACT

OBJECTIVE: This study aimed to assess the evolution of nutritional status, parenteral nutrition (PN) composition, and PN dependence index (PNDI) in children under 2 years old with intestinal failure (IF) and malnutrition.

METHODS: This retrospective cohort included patients admitted between November 1, 2016, and August 31, 2021, with IF, age ≤24 months, and weight-for-age (Wt/A) <-2 standard deviation with a follow-up of 12 months. Data collected included demographic, anthropometric, biochemical, and nutritional information. The PNDI was compared between enteral autonomy (EA) and nonenteral autonomy (non-EA) groups.

RESULTS: Thirty patients (16 males, 53.33%) were included, and short bowel syndrome (SBS) was the leading cause of IF (n = 27, 90%). The mean age at admission was 7.23 ± 3.90 months, and 36.66% of the patients had a conjugated bilirubin (CB) level >2 mg/dL; 87% had a Wt/A z-score <-3 and 90% had a height-for-age (Ht/A) z-score <-3. At 5 months, the mean Wt/A z-score improved to -1.82. At admission, median protein, lipid, and glucose intake on PN were 3, 1.6, and 17.27 g/kg/day, respectively. In the PNDI analysis, the EA group had a mean index of 141% versus 158% for the non-EA group at admission, with no statistical differences. From the sixth month onward, the EA group showed a significantly lower PNDI (50% vs. 108% for non-EA patients; p = 0.032). Both groups demonstrated adequate nutritional recovery.

CONCLUSION: Adequate multidisciplinary care can reverse severe malnutrition, and the PNDI may be a predictor of EA.

PMID:39963728 | DOI:10.1002/jpn3.70018

Open Forum Infect Dis. 2025 Jan 28;12(2):ofaf049. doi: 10.1093/ofid/ofaf049. eCollection 2025 Feb.

ABSTRACT

BACKGROUND: Myroides species, Gram-negative bacilli from the Flavobacteriaceae family, are typically considered low-virulence pathogens but have previously been described as extensively drug-resistant. This study investigates the clinical features and outcomes of Myroides infections.

METHODS: We conducted a retrospective cohort study of patients hospitalized at Cleveland Clinic with Myroides infection. Infections were defined as a positive Myroides culture from a sterile site that were treated with an antibiotic to which the isolate was susceptible. Controls were hospitalized patients with a positive culture for Myroides, who did not meet the definition for infection. Survival for infected patients and uninfected controls was compared using Cox proportional hazards regression.

RESULTS: Between January 2015 and September 2023, 52 positive Myroides species cultures were identified, with 21 deemed infections. A higher proportion of Myroides-infected patients than controls had diabetes mellitus. The most common infections were skin/soft-tissue infections (42.8%), osteomyelitis (33.3%), and urinary tract infections (19%); and 28.5% were bacteremic infections. All isolates were resistant to aminoglycosides, but the majority were susceptible to trimethoprim-sulfamethoxazole (81%), ciprofloxacin (57%), and meropenem (68%). The main antimicrobial treatments provided were meropenem, ciprofloxacin, and trimethoprim-sulfamethoxazole. A significant difference in survival was not found between patients with Myroides infection and uninfected controls (hazard ratio, 3.42; 95% confidence interval, .63-18.74; P = .16).

CONCLUSIONS: All patients in this study had reasonable treatment options, belying previous reports of extensive antibiotic resistance in Myroides. Our small study did not detect a statistically significant decrease in survival among Myroides-infected patients compared to controls.

PMID:39963698 | PMC:PMC11832043 | DOI:10.1093/ofid/ofaf049

Open Forum Infect Dis. 2025 Jan 17;12(2):ofaf024. doi: 10.1093/ofid/ofaf024. eCollection 2025 Feb.

ABSTRACT

BACKGROUND: Specialty societies, including the Infectious Diseases Society of America, strive to address gender and racial inequities in professional advancement. Microaggressions remain a persistent and pervasive barrier to these goals. Nonprofessional speaker introductions are a manifestation of race- and gender-based microaggressions, which have not been previously assessed at IDWeek. We assessed disparities in speaker introductions at IDWeek over a 7-year period that included formal gender equity initiatives introduced in 2016.

METHODS: We conducted a retrospective observational study of video-recorded IDWeek speaker introductions from 2013 to 2019. Trained coders reviewed presentation video archives to assess a primary outcome of nonprofessional introductions: when a speaker’s professional title was not used as the first introduction. We used descriptive statistics, Fisher exact tests, Cochrane-Armitage trend tests, and multivariable logistic regression to characterize relationships between speaker introductions and presentation year, speaker demographics, and speaker-moderator demographic concordance.

RESULTS: Of 1940 videos reviewed, 48.9% of IDWeek speakers received nonprofessional introductions during and before 2016 vs 41.5% of speakers after 2016 (P = .0013). There was an increasing linear trend in the frequency of professional introductions by speaker age group from 47.1% for age <40 years to 65.3% for age >60 years (P < .0001). White moderators more frequently used nonprofessional introductions than moderators from backgrounds underrepresented in medicine (47.7% vs 29.1%, P = .0014). Women-men speaker-moderator pairs had more nonprofessional introductions (54.6%, P < .001).

CONCLUSIONS: In the largest assessment of microaggressions in speaker introductions at a national medical specialty conference, we highlighted some progress over time and ample opportunity to further standardize equitable speaker introductions, especially for women and junior speakers.

PMID:39963695 | PMC:PMC11830950 | DOI:10.1093/ofid/ofaf024

Front Aging. 2025 Feb 3;6:1297704. doi: 10.3389/fragi.2025.1297704. eCollection 2025.

ABSTRACT

This article emphasizes the advantages of using a within-subject experimental design to assess the impact of salient visual cues on the comprehension and acceptability of computerized cognitive training (CCT) instructions among older adults. The study would involve participants aged 65 and above, who will engage in an online experiment presenting two sets of instructions for serious games: one with salient visual cues and one without. This within-subject design eliminates the need for random assignment, improves internal consistency, and enhances statistical power. Participants serve as their own controls, providing a more robust comparison of how visual cues affect instruction comprehension and software acceptance. The primary objective is to identify indicators of acceptability for CCT serious games and to evaluate how well participants comprehend the instructions, influencing their intention to use the software. The hypothesis suggests that salient visual cues will improve instruction comprehension and foster greater software acceptability. By focusing on this design method, the study aims to enhance the engagement of older adults in cognitive training programs, reducing dropout rates. This research offers valuable insights into methodological strengths that can be applied in future studies to improve the usability and acceptance of CCT tools for older adults without cognitive impairments.

PMID:39963688 | PMC:PMC11830709 | DOI:10.3389/fragi.2025.1297704

Front Aging. 2025 Feb 3;6:1513936. doi: 10.3389/fragi.2025.1513936. eCollection 2025.

ABSTRACT

Regular physical activity offers benefits like enhanced bone density, which often persists post-retirement. However, retirement can lead to weight gain and changes in quality of life due to reduced physical activity. Therefore, this study investigates the long-term effects of elite athletic experience by comparing retired Jordanian male elite athletes (ages 40-50) with non-athletes of the same age. The differences were explored in weight changes, bone density, quality of life, happiness, stress, insomnia, physical activity, and dietary intake to understand how martial arts impact these health dimensions.

METHODS: A descriptive case-control study was conducted among 30 retired male elite athletes and 20 age-matched non-athletes. Bone density and body composition were measured using dual-energy X-ray absorptiometry (DEXA) scans. Additional assessments included anthropometric measurements, a 3-day dietary recall, physical activity (International Physical Activity Questionnaire), quality of life (WHOQOL), happiness (Subjective Happiness Scale), stress (Perceived Stress Scale), and insomnia (Insomnia Severity Index).

RESULTS: Retired athletes showed significantly higher Z-scores for the left femur (neck and total) and the AP spine, with p-values <0.05. Among non-athletes, 65% had normal bone density with a Z-score ≥ -1.9 and a T-score > -1.1, 20% had abnormal bone density with a Z-score < -1.9, and 15% had osteopenia with a T-score between -1.1 and -2.4. In contrast, 100% of retired athletes had normal bone density with a Z-score ≥ -1.9 and a T-score > -1.1. Retired athletes exhibited greater weight changes than non-athletes, with a p-value <0.05; the average weight gain among retired athletes was 18.548 kg, and the mean weight gain among non-athletes was 4.3 kg. There were statistically significant mean differences in perceived stress levels between retired athletes and non-athletes with a p-value <0.05. In contrast, there were no statistically significant mean differences between the groups in quality of life, subjective happiness, and the Insomnia Severity Index.

CONCLUSION: The study reveals that retired elite athletes maintain better bone density but face greater weight gain and stress than their non-athlete counterparts. Both groups enjoy a high quality of life and low levels of insomnia. These findings underscore the importance of continued physical activity for health and suggest that both retired athletes and non-athletes should adopt a balanced lifestyle to manage weight and stress effectively.

PMID:39963687 | PMC:PMC11830723 | DOI:10.3389/fragi.2025.1513936

Endocrinol Metab (Seoul). 2025 Feb 12. doi: 10.3803/EnM.2024.2181. Online ahead of print.

ABSTRACT

In this cross-sectional study, we aimed to investigate the relationship between steatotic liver disease (SLD) and retinal abnormalities in a cohort undergoing health screening. Our study included 353,607 participants who underwent fundus photography and abdominal ultrasonography at least once at the Kangbuk Samsung Health Promotion Center from 2002 to 2022. After adjusting for age and sex, the risk of retinal vein occlusion (RVO) significantly increased with the presence of non-alcoholic fatty liver disease, metabolic dysfunction-associated fatty liver disease, and metabolic dysfunction-associated SLD, with odds ratios of 1.259 (95% confidence interval [CI], 1.050 to 1.510), 1.498 (95% CI, 1.249 to 1.796), and 1.342 (95% CI, 1.121 to 1.605), respectively. However, these associations weakened after adjusting for body mass index. No statistically significant associations were observed with other retinal disorders after adjusting for age, sex, and other confounding factors. Our findings suggest that obesity may mediate the relationship between SLD and RVO, while other retinal abnormalities may be more closely associated with known risk factors rather than SLD itself.

PMID:39962357 | DOI:10.3803/EnM.2024.2181

J Rural Health. 2025 Jan;41(1):e70005. doi: 10.1111/jrh.70005.

ABSTRACT

PURPOSE: To describe the impact from the closure of a rural community’s only health center on chronic health conditions, access to care, and quality of care received from the patient’s perspective.

METHODS: This was a cross-sectional telephone survey. Adult patients established with a rural health center participated in a 19-item survey at 6 months post-closure to collect data on perceived impacts. Data were summarized using descriptive statistics.

FINDINGS: There were 249 patients contacted, with 131 participants (52.6% response rate). Participants had a median age of 63 years (interquartile range, 44.5-73.0), and the majority were female (n = 82; 62.6%) and had been established with the health center for over 10 years (n = 79; 60.3%). At 6 months, the majority of participants had established care with another health center (n = 91; 69.5%). Most participants felt that the closure made it more difficult to access care (n = 106; 80.9%) but did not feel the closure reduced the quality of care they were receiving (n = 42; 32.1%). There was no impact perceived on the management of most health conditions, except chronic pain where worsening was the most selected option.

CONCLUSIONS: Patients were able to successfully transition care after closure of their local health center, and most did not perceive an impact on the quality of care received. However, participants reported reduced access to care. Future research might repeat this process, perhaps using a mixed-method approach, to intentionally capture nuances in patient behavior, experiences, and attitudes following the loss of primary care services in rural communities.

PMID:39962356 | DOI:10.1111/jrh.70005