Tag: statistics

BMJ Open. 2023 Dec 18;13(12):e076735. doi: 10.1136/bmjopen-2023-076735.

ABSTRACT

OBJECTIVE: To characterise surgical site infections (SSIs) after open surgery in the UK’s National Health Service.

DESIGN: Retrospective cohort analysis of electronic records of patients from Clinical Practice Research Datalink, linked with Hospital Episode Statistics’ secondary care datasets.

SETTING: Clinical practice in the community and secondary care.

PARTICIPANTS: Cohort of 50 000 adult patients who underwent open surgery between 2017 and 2022.

OUTCOME MEASURES: Incidence of SSI, clinical outcomes, patterns of care and costs of wound management.

RESULTS: 11% (5281/50 000) of patients developed an SSI a mean of 18.4±14.7 days after their surgical procedure, of which 15% (806/5281) were inpatients and 85% (4475/5281) were in the community after hospital discharge. The incidence of SSI varied according to anatomical site of surgery. The incidence also varied according to a patient’s risk and whether they underwent an emergency procedure. SSI onset reduced the 6 months healing rate by a mean of 3 percentage points and increased time to wound healing by a mean of 15 days per wound. SSIs were predominantly managed in the community by practice and district nurses and 16% (850/5281) of all patients were readmitted into hospital. The total health service cost of surgical wound management following SSI onset was a mean of £3537 per wound ranging from £2542 for a low-risk patient who underwent an elective procedure to £4855 for a high-risk patient who underwent an emergency procedure.

CONCLUSIONS: This study provides important insights into several aspects of SSI management in clinical practice in the UK that have been difficult to ascertain from surveillance data. Surgeons are unlikely to be fully aware of the true incidence of SSI and how they are managed once patients are discharged from hospital. Current SSI surveillance services appear to be under-reporting the actual incidence.

PMID:38110388 | DOI:10.1136/bmjopen-2023-076735

BMJ Open. 2023 Dec 18;13(12):e079874. doi: 10.1136/bmjopen-2023-079874.

ABSTRACT

OBJECTIVES: This study aims to investigate the incidence of and factors associated with irritable bowel syndrome (IBS) among resident physicians in standardised training at eight traditional Chinese medicine (TCM) hospitals in China.

DESIGN: A cross-sectional survey was administered to resident physicians in their first to third years of standardised training at eight TCM hospitals.

PARTICIPANTS AND SETTING: A total of 514 resident physicians in standardised training were included.

MEASURES: The questionnaire consisted of two sections, namely: section A collected basic information, and section B included the four-item Perceived Stress Scale (PSS-4), the Patient Health Questionnaire-4 (PHQ-4), the Pittsburgh Sleep Quality Index (PSQI) and the Rome IV criteria for IBS. Univariate and multivariate logistic regression models were constructed to assess the associations of age, sex, body mass index, stress, depression, anxiety, sleep quality and IBS.

RESULTS: Of the included resident doctors, 77.2% were female, 20.4% were obese or underweight and 8.6% had symptoms consistent with a diagnosis of IBS. There were no statistically significant differences in lifestyle factors (night shift work, overtime work or working efficiency during the COVID-19 pandemic) between patients with IBS and participants without IBS (hereafter, non-IBS participants) (p=0.429, p=0.572 or p=0.464, respectively). Notably, compared with non-IBS participants, patients with IBS had significantly higher mean scores on the PSS-4 and PHQ-4 (p=0.028 and p=0.012, respectively); however, there was not a significant difference in PSQI scores between these two groups (p=0.079). Depression symptoms were significantly associated with IBS (unadjusted OR 0.498, 95% CI 0.265 to 0.935, p=0.030).

CONCLUSION: These findings suggest that IBS is common among resident physicians in standardised training. Future studies should investigate emotional distress, especially stress and depression, in the development of prevention or treatment of IBS.

PMID:38110383 | DOI:10.1136/bmjopen-2023-079874

BMJ Open. 2023 Dec 18;13(12):e064335. doi: 10.1136/bmjopen-2022-064335.

ABSTRACT

OBJECTIVES: Antimicrobial resistant (AMR) infections are a major public health problem and the burden on population level is not yet clear. We developed a method to calculate the excess burden of resistance which uses country-specific parameter estimates and surveillance data to compare the mortality and morbidity due to resistant infection against a counterfactual (the expected burden if infection was antimicrobial susceptible). We illustrate this approach by estimating the excess burden for AMR (defined as having tested positive for extended-spectrum beta-lactamases) urinary tract infections (UTIs) caused by E. coli in the Netherlands in 2018, which has a relatively low prevalence of AMR E. coli, and in Italy in 2016, which has a relatively high prevalence.

DESIGN: Excess burden was estimated using the incidence-based disability-adjusted life-years (DALYs) measure. Incidence of AMR E. coli UTI in the Netherlands was derived from ISIS-AR, a national surveillance system that includes tested healthcare and community isolates, and the incidence in Italy was estimated using data reported in the literature. A systematic literature review was conducted to find country-specific parameter estimates for disability duration, risks of progression to bacteraemia and mortality.

RESULTS: The annual excess burden of AMR E. coli UTI was estimated at 3.89 and 99.27 DALY/100 0000 population and 39 and 2786 excess deaths for the Netherlands and Italy, respectively.

CONCLUSIONS: For the first time, we use country-specific and pathogen-specific parameters to estimate the excess burden of resistant infections. Given the large difference in excess burden due to resistance estimated for Italy and for the Netherlands, we emphasise the importance of using country-specific parameters describing the incidence and disease progression following AMR and susceptible infections that are pathogen specific, and unfortunately currently difficult to locate.

PMID:38110375 | DOI:10.1136/bmjopen-2022-064335

Retina. 2023 Dec 14. doi: 10.1097/IAE.0000000000003997. Online ahead of print.

ABSTRACT

PURPOSE: to demonstrate through a diagnostic test used as a new preoperative assessment, that trocar insertion for pars plana vitrectomy could be safely placed at a distance greater than 4.0 mm in highly myopic eyes to facilitate the surgical maneuvers.

METHODS: 30 eyes of 30 patients were tested with a biometer for the axial length measurement and with ultrasound biomicroscopy (UBM) to measure the pars plana length. Pars plana lengths of highly myopic eyes were then compared with those of emmetropic eyes. The surgeon also measured the pars plana of highly myopic eyes intraoperatively and compared it with ultrasound measurements to assess UBM reliability.

RESULTS: The mean AXL was 23.81mm (SD ±0.30) in the control group and 31.11 mm (SD ±0.56) in the myopic group. The mean pars plana length was 4.96 mm (SD ±0.19) in control eyes and 6.65 (SD ±0.36) in myopic eyes. An extremely significant statistical difference (p < 0.001) was obtained by comparing the length of pars plana between control eyes and myopic eyes. The results of pars plana measurements were 6.65 mm SD ±0.36 (UBM) and 6.66 mm SD ±0.34 (intraoperative measurements) in myopic eyes. The statistical comparison of the measurements in these two groups did not give a statistically significant result (p = 0.950).

CONCLUSIONS: UBM is a reliable technique to calculate the length of pars plana in highly myopic eyes, where this parameter is significantly greater than that of emmetropic eyes. Trocars insertion for pars plana vitrectomy may be performed, in eyes with axial length greater than 30mm, in relative safety at a distance to limbus higher than 4mm.

PMID:38109723 | DOI:10.1097/IAE.0000000000003997

Stat Med. 2023 Dec 18. doi: 10.1002/sim.9972. Online ahead of print.

ABSTRACT

We focus on Bayesian inference for survival probabilities in a prime-boost vaccination regime in the development of an Ebola vaccine. We are interested in the heterologous prime-boost regimen (unmatched vaccine deliverys using the same antigen) due to its demonstrated durable immunity, well-tolerated safety profile, and suitability as a population vaccination strategy. Our research is motivated by the need to estimate the survival probability given the administered dosage. To do so, we establish two key relationships. Firstly, we model the connection between the designed dose concentration and the induced antibody count using a Bayesian response surface model. Secondly, we model the association between the antibody count and the probability of survival when experimental subjects are exposed to the Ebola virus in a controlled setting using a Bayesian probability of survival model. Finally, we employ a combination of the two models with dose concentration as the predictor of the survival probability for a future vaccinated population. We implement our two-level Bayesian model in Stan, and illustrate its use with simulated and real-world data. Performance of this model is evaluated via simulation. Our work offers a new application of drug synergy models to examine prime-boost vaccine efficacy, and does so using a hierarchical Bayesian framework that allows us to use dose concentration to predict survival probability.

PMID:38109707 | DOI:10.1002/sim.9972

J Urol. 2023 Dec 18:101097JU0000000000003825. doi: 10.1097/JU.0000000000003825. Online ahead of print.

ABSTRACT

PURPOSE: To examine the association of extraprostatic extension (EPE) with biochemical recurrence (BCR) separately in men with grade group 1 (GG1) and GG2 prostate cancer (PCa) treated with radical prostatectomy.

MATERIALS AND METHODS: We reviewed our institutional database of patients who underwent radical prostatectomy for PCa between 2005 and 2022 and identified patients with GG1 and GG2 disease on final pathology. Fine-Gray competing risk models with an interaction between EPE (yes vs no) and grade group (GG1 vs GG2) were used to examine the relationship between disease group and BCR-free survival.

RESULTS: The cohort consisted of 6309 men, of whom 169/2740 (6.2%) with GG1 disease had EPE while 1013/3569 (28.4%) with GG2 disease had EPE. Median follow up was 4 years. BCR occurred in 400/6309 (6.3%) patients. For men with GG1, there was no statistically significant difference in BCR-free survival for men with vs without EPE (subdistribution hazard ratio [SHR] = 0.88; 95% CI: 0.37-2.09). However, for GG2 patients BCR-free survival was significantly worse for those with vs without EPE (SHR = 1.97, 95% CI: 1.54-2.52).

CONCLUSION: Although there are a subset of GG1 PCa’s capable of invading through the prostatic capsule, patients with GG1 PCa and EPE at prostatectomy experience similar biochemical recurrence and survival outcomes compared to GG1 patients without EPE. However, among men with GG2 EPE connotes a worse prognosis.

PMID:38109699 | DOI:10.1097/JU.0000000000003825

J Clin Oncol. 2023 Dec 18:JCO2301586. doi: 10.1200/JCO.23.01586. Online ahead of print.

ABSTRACT

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The LYMA trial demonstrated the benefit of rituximab maintenance (RM) in first-line young patients with mantle-cell lymphoma. In this prolonged follow-up of 7.5 years (95% CI, 7.4 to 7.7) from inclusion, the median progression-free survival (PFS) and overall survival (OS) for the full population were not reached (NR) with a 7-year PFS of 55.5% (95% CI, 49.5 to 61) and OS of 69.5% (95% CI, 63.8 to 74.5). The EFS remained statistically superior in favor of RM (median NR v 5.8 years, P < .0001; HR, 0.39 [95% CI, 0.52 to 0.6] and 7-year estimate, 76.2% versus 46% for RM and observation, respectively). Similarly, RM prolonged PFS (estimated PFS at 7 years, 78.5% v 47.4% and HR, 0.36 [95% CI, 0.23 to 0.56] for RM and observation, respectively, P < .0001). The 7-year OS estimate was 83.2% versus 72.2%, respectively (P = .088, HR, 0.63 [95% CI, 0.37 to 1.08]). Cause of death was not significantly distinct between the two groups, with lymphoma being the leading cause with a very low rate of infection-related death. Overall, the PFS benefit of RM after autologous stem cell transplantation remains after 7-year follow-up, and RM was not associated with an increase in infection-related mortality, making this strategy a safe standard of care with long-term follow-up.

PMID:38109684 | DOI:10.1200/JCO.23.01586

Anesthesiology. 2023 Dec 18. doi: 10.1097/ALN.0000000000004879. Online ahead of print.

ABSTRACT

BACKGROUND: Mechanical power (MP), the rate of mechanical energy (ME) delivery, is a recently introduced unifying ventilator parameter consisting of tidal volume, airway pressures, and respiratory rates, which predicts pulmonary complications in several clinical contexts. However, ME has not been previously studied in the perioperative context and neither parameter has been studied in the context of thoracic surgery utilizing one lung ventilation.

METHODS: The relationships between mechanical energy variables and postoperative pulmonary complications were evaluated in this post hoc analysis of data from a multicenter randomized clinical trial of lung resection surgery conducted between 2020 and 2021 (n=1,170). Time-weighted average MP (MPTWA) and ME (the area under the MP time curve) were obtained for individual patients. The primary analysis was the association of MPTWA and ME with pulmonary complications within 7 postoperative days. Multivariable logistic regression was performed to examine the relationships between energy variables and the primary outcome.

RESULTS: In 1,055 patients analyzed, pulmonary complications occurred in 41% (431/1055). The median (interquartile ranges) ME and MPTWA in patients who developed postoperative pulmonary complications (PPC) vs those who did not were 1,146 (811‒1530) J vs 924 (730‒1240) J (P<0.001), and 6.9 (5.5‒8.7) J/min vs 6.7 (5.2‒8.5) J/min (P=0.091), respectively. ME was independently associated with PPCs (ORadj 1.44 [95%CI 1.16‒1.80], P=0.001). However, the association between MPTWA and PPCs was time dependent and MPTWA was significantly associated with PPCs in cases utilizing longer periods of mechanical ventilation (≥210 minutes; ORadj 1.46 [95%CI 1.11‒1.93], P=0.007). Normalization of ME and MPTWA to either predicted body weight or to respiratory system compliance did not alter these associations.

CONCLUSIONS: ME and, in cases requiring longer periods of mechanical ventilation, MP were independently associated with PPC in thoracic surgery.

PMID:38109657 | DOI:10.1097/ALN.0000000000004879

J Vis. 2023 Dec 1;23(15):56. doi: 10.1167/jov.23.15.56.

ABSTRACT

When we enter a dark place like a tunnel from a bright exterior, our visual sensitivities take some time to adapt to the lower light level. However, there have been few reports about how quickly our sensitivities of luminance and chromaticity discrimination recover in this situation. This study aimed to quantify the time course of discrimination sensitivity for luminance and chromaticity directions after an abrupt decrease in background luminance. In each trial, the background luminance dropped from 100 cd/m² to 1 cd/m². Then, one target and three reference stimuli with different colors were presented under four stimulus onset asynchrony (SOA) conditions. The observer was asked to discriminate the target stimulus from the reference stimuli. The results showed that discrimination sensitivity was lowest right after the background luminance change and gradually improved with SOAs. However, sensitivity recovery differed across color directions, with the most improvement in luminance, followed by S, and negligible change in L-M. There was a statistically significant difference between +S and ±(L-M) sensitivities, indicating that the sensitivity recovery after the sudden background luminance change differed between chromaticity directions. Based on the comparison with previous studies, we speculate that both adaptation and masking may contribute to the temporal change of discrimination sensitivities.

PMID:38109592 | DOI:10.1167/jov.23.15.56

J Vis. 2023 Dec 1;23(15):80. doi: 10.1167/jov.23.15.80.

ABSTRACT

When a person views a color sample, they can usually provide a color term for it. But will that color term allow someone else to understand which sample was named? We examined color understanding using a Color Communication Game, in which one person (the “sender”) names 30 color samples as in any color-naming study, then another person (the “receiver”) chooses the sample they think the sender intended to communicate. The receiver cannot always guess the right sample, and no choice strategy will do better than randomly choosing among the samples the receiver called by that term. When 70 English-speaking dyads and 63 Somali-speaking dyads played the game, receivers did not perform randomly. Instead, they systematically chose “focal” samples near the centers of their color term distributions. When the senders’ named samples were compared directly to the receivers’ chosen samples, the systematic distribution of receiver choices revealed color categories, which appeared without any statistical analysis of the players’ terms. Simulation of receiver choices based on senders’ color names showed that both Somali-speaking and English-speaking participants knew more color terms than the ones they used in color-naming. Our Color Communication Game showed that color-naming experiments underestimate color understanding: people understand colors categorically, but they express colors using multiple synonymous color terms that are well-understood by others.

PMID:38109568 | DOI:10.1167/jov.23.15.80