Assessment of the Performance of Imputation Techniques in Observational Studies with Two Measurements

: In observational studies with two measurements when the measured outcome pertains to a health related quality of life (HRQoL) variable, one motivation of the research may be to determine the potential predictors of the mean change of the outcome of interest. It is very common in such studies for data to be missing, which can bias the results. Different imputation techniques have been proposed to cope with missing data in outcome variables. We compared five analysis approaches (Complete Case, Available Case, K- Nearest Neighbour, Propensity Score, and a Markov Chain Monte Carlo algorithm) to assess their performance when handling missing data at different missingness rates and mechanisms (MCAR, MAR and MNAR). These strategies were applied to a pre-post study of patients with Chronic Obstructive Pulmonary Disease. We analyzed the relationship of the changes in subjects HRQoL over one year with clinical and socio-demographic characteristics. A simulation study was also performed to illustrate the performance of the imputation methods. Relative and standardized bias was assessed on each scenario. For all missingness mechanisms, not imputing and using MCMC method, both combined with mixed-model analysis, showed lowest standardized bias. Conversely, Propensity Score showed worst bias values. When missingness pattern is MCAR or MAR and rate small, we recommend using mixed models. Nevertheless, when missingness percentage is high, in order to gain sample size and statistical power, MCMC is preferred, although there are no bias differences compared with the mixed models without imputation. For a MNAR scenario, a further sensitivity analysis should be made

Inputazio tekniken errendimenduaren ebaluazioa bi neurketako luzeranzko datuetan

Neurketa errepikatuetan oinarrituriko behaketa-ikerketak menpeko aldagaien aldaketak denboran zehar aztertzeko erabiltzen dira. Bi neurketa baizik bakarrik egiten ez direnean, ikerketa helburu nagusietariko bat izan daiteke menpeko aldagaiaren batez besteko aldaketa aurresaten dituzten faktoreak zehaztea. Menpeko aldagaian faltako balioak ohikoak dira ikerketa mota hauetan, behaturiko datuen analisiaren emaitzak alboratuak gerta daitezkeelarik. Lan honetan inputazio teknika desberdinak proposatuko ditugu datu-analisiak egiterakoan faltako balioei aurre egiteko aukera gisa. Hiru inputazio metodoren errendimendua aztertu dugu (K-Nearest Neighbor, Propensity Score eta Markov Chain Monte Carlo algoritmoak), faltako balioek datu multzo osoaren % 10a eta % 30a osatzen dutenean

Validation of a screening questionnaire for hip and knee osteoarthritis in old people

Es reproducción del documentoa publicado en http://dx.doi.org/10.1186/1471-2474-8-84Background: To develop a sensitive and specific screening tool for knee and hip osteoarthritis in the general population of elderly people. Methods: The Knee and Hip OsteoArthritis Screening Questionnaire (KHOA- SQ) was developed based on previous studies and observed data and sent to 11,002 people aged 60 to 90 years, stratified by age and gender, who were selected by random sampling. Algorithms of the KHOA- SQ were created. Respondents positive for knee or hip OA on the KHOA- SQ were invited to be evaluated by an orthopedic surgeon. A sample of 300 individuals negative for knee or hip OA on the KHOA- SQ were also invited for evaluation. Sensitivity and specificity were determined for the KHOA- SQ, as well as for KHOA- SQ questions. Classification and Regression Tree analysis was used to find alternative screening algorithms from the questionnaire. Results: Of 11,002 individuals contacted, 7,577 completed the KHOA- SQ. Of 1,115 positive for knee OA, on the KHOA- SQ, 710 ( 63.6%) were diagnosed with it. For hip OA, 339 of the 772 who screened positive ( 43.9%) were diagnosed it. Sensitivity for the hip algorithm was 87.4% and specificity 59.8%; for the knee, sensitivity was 94.5% and specificity 43.8%. Two alternative algorithms provided lower specificity. Conclusion: The KHOA- SQ offers high sensitivity and moderate specificity. Although this tool correctly identifies individuals with knee or hip OA, the high false positive rate could pose problems. Based on our questions, no better algorithm was found

BODE-Index vs HADO-Score in Chronic Obstructive Pulmonary Disease: Which one to use in general practice?

<p>Abstract</p> <p>Background</p> <p>Forced expiratory volume in one second (FEV₁) is used to diagnose and establish a prognosis in chronic obstructive pulmonary disease (COPD). Using multi-dimensional scores improves this predictive capacity.Two instruments, the BODE-index (<b>B</b>ody mass index, <b>O</b>bstruction, <b>D</b>yspnea, <b>E</b>xercise capacity) and the HADO-score (<b>H</b>ealth, <b>A</b>ctivity, <b>D</b>yspnea, <b>O</b>bstruction), were compared in the prediction of mortality among COPD patients.</p> <p>Methods</p> <p>This is a prospective longitudinal study. During one year (2003 to 2004), 543 consecutively COPD patients were recruited in five outpatient clinics and followed for three years. The endpoints were all-causes and respiratory mortality.</p> <p>Results</p> <p>In the multivariate analysis of patients with FEV₁< 50%, no significant differences were observed in all-cause or respiratory mortality across HADO categories, while significant differences were observed between patients with a lower BODE (less severe disease) and those with a higher BODE (greater severity). Among patients with FEV₁≥ 50%, statistically significant differences were observed across HADO categories for all-cause and respiratory mortality, while differences were observed across BODE categories only in all-cause mortality.</p> <p>Conclusions</p> <p>HADO-score and BODE-index were good predictors of all-cause and respiratory mortality in the entire cohort. In patients with severe COPD (FEV₁< 50%) the BODE index was a better predictor of mortality whereas in patients with mild or moderate COPD (FEV₁≥ 50%), the HADO-score was as good a predictor of respiratory mortality as the BODE-index. These differences suggest that the HADO-score and BODE-index could be used for different patient populations and at different healthcare levels, but can be used complementarily.</p

Factors Associated With Peripheral Nerve Injury After Pelvic Laparoscopy: The Importance of Surgical Positioning

BACKGROUND: Nerve damage after abdominal and pelvic surgery is rare but potentially serious. The incidence of peripheral nerve injury is difficult to assess, and rates of between 0.02% and 21% have been cited in the literature. Signs and symptoms of this type of injury may appear immediately after surgery or a few days later. PURPOSE: This study was developed to assess the rate of peripheral nerve injury after pelvic laparoscopy and to identify associated risk factors. METHODS: A pilot prospective cohort study was conducted between March 2018 and April 2019 on 101 patients with a 1-month follow-up using two semistructured clinical interviews. We carried out a descriptive analysis followed by univariable and multivariable logistic regression analyses. RESULTS: Thirteen patients were found to have peripheral nerve injuries, representing a rate of 12.9%. Overall, 14 injuries (five severe and nine mild) were detected. One patient had two mild injuries. In this study, the risk of injury was found to increase 1.77-fold (OR = 1.77, 95% CI [1.13, 2.76], p = .007) for each hour the patient was in the Trendelenburg position. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: The longer the patient is in the Trendelenburg position, the greater the risk of peripheral nerve damage. Patients aged 60 years or less also face a higher risk of nerve injury.This study was supported by a 600-euro grant from the Basque Foundation for Health Innovation and Research

Five-year follow-up mortality prognostic index for colorectal patients

Correction to: Five-year follow-up mortality prognostic index for colorectal patients. Int J Colorectal Dis. 2023 Jun 24;38(1):177. doi: 10.1007/s00384-023-04472-z. PMID: 37354325.Purpose: To identify 5-year survival prognostic variables in patients with colorectal cancer (CRC) and to propose a survival prognostic score that also takes into account changes over time in the patient's health-related quality of life (HRQoL) status. Methods: Prospective observational cohort study of CRC patients. We collected data from their diagnosis, intervention, and at 1, 2, 3, and 5 years following the index intervention, also collecting HRQoL data using the EuroQol-5D-5L (EQ-5D-5L), European Organization for Research and Treatment of Cancer's Quality of Life Questionnaire-Core 30 (EORTC-QLQ-C30), and Hospital Anxiety and Depression Scale (HADS) questionnaires. Multivariate Cox proportional models were used. Results: We found predictors of mortality over the 5-year follow-up to be being older; being male; having a higher TNM stage; having a higher lymph node ratio; having a result of CRC surgery classified as R1 or R2; invasion of neighboring organs; having a higher score on the Charlson comorbidity index; having an ASA IV; and having worse scores, worse quality of life, on the EORTC and EQ-5D questionnaires, as compared to those with higher scores in each of those questionnaires respectively. Conclusions: These results allow preventive and controlling measures to be established on long-term follow-up of these patients, based on a few easily measurable variables. Implications for cancer survivors: Patients with colorectal cancer should be monitored more closely depending on the severity of their disease and comorbidities as well as the perceived health-related quality of life, and preventive measures should be established to prevent adverse outcomes and therefore to ensure that better treatment is received. Trial registration: ClinicalTrials.gov identifier: NCT02488161.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported in part by grants from the Instituto de Salud Carlos III and the European Regional Development Fund (PS09/00314, PS09/00910, PS09/00746, PS09/00805, PI09/90460, PI09/90490, PI09/90453, PI09/90441, PI09/90397); the Spanish Ministry of the Economy (PID2020-115738 GB-I00); the Departments of Health (2010111098) and Education, Language Policy and Culture (IT1456-22; IT1598-22; IT-1187–19) of the Basque Government; the Research Committee of Galdakao Hospital; the REDISSEC (Red de Investigación en Servicios de Salud en Enfermedades Crónicas) thematic network of the Instituto de Salud Carlos III; and the Department of Education of the Basque Government through the Consolidated Research Group MATHMODE (IT1456-22) and the Basque Government through BMTF “Mathematical Modeling Applied to Health” Project.S

Anxiety, depression, health-related quality of life, and mortality among colorectal patients: 5-year follow-up

Purpose Health-related quality of life (HRQoL) measurement represents an important outcome in cancer patients. We describe the evolution of HRQoL over a 5-year period in colorectal cancer patients, identifying predictors of change and how they relate to mortality. Methods Prospective observational cohort study including colorectal cancer (CRC) patients having undergone surgery in nineteen public hospitals who were monitored from their diagnosis, intervention and at 1-, 2-, 3-, and 5-year periods thereafter by gathering HRQoL data using the EuroQol-5D-5L (EQ-5D-5L), European Organization for Research and Treatment of Cancer's Quality of Life Questionnaire-Core 30 (EORTC-QLQ-C30), and Hospital Anxiety and Depression Scale (HADS) questionnaires. Multivariable generalized linear mixed models were used. Results Predictors of Euroqol-5D-5L (EQ-5D-5L) changes were having worse baseline HRQoL; being female; higher Charlson index score (more comorbidities); complications during admission and 1 month after surgery; having a stoma after surgery; and needing or being in receipt of social support at baseline. For EORTC-QLQ-C30, predictors of changes were worse baseline EORTC-QLQ-C30 score; being female; higher Charlson score; complications during admission and 1 month after admission; receiving adjuvant chemotherapy; and having a family history of CRC. Predictors of changes in HADS anxiety were being female and having received adjuvant chemotherapy. Greater depression was associated with greater baseline depression; being female; higher Charlson score; having complications 1 month after intervention; and having a stoma. A deterioration in all HRQoL questionnaires in the previous year was related to death in the following year. Conclusions These findings should enable preventive follow-up programs to be established for such patients in order to reduce their psychological distress and improve their HRQoL to as great an extent as possible.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported in part by grants from the Instituto de Salud Carlos III and the European Regional Development Fund (PS09/00314, PS09/00910, PS09/00746, PS09/00805, PI09/90460, PI09/90490, PI09/90453, PI09/90441, PI09/90397); the Departments of Health (2010111098) and Education, Language Policy and Culture (IT620-13) of the Basque Government; the Research Committee of Hospital Galdakao; and the thematic network-REDISSEC (Red de Investigacion en Servicios de Salud en Enfermedades Cronicas)-of the Instituto de Salud Carlos III

Factors that influence treatment delay in patients with colorectal cancer

A prospective study was performed of patients diagnosed with colorectal cancer (CRC), distinguishing between colonic and rectal location, to determine the factors that may provoke a delay in the first treatment (DFT) provided.2749 patients diagnosed with CRC were studied. The study population was recruited between June 2010 and December 2012. DFT is defined as time elapsed between diagnosis and first treatment exceeding 30 days.Excessive treatment delay was recorded in 65.5% of the cases, and was more prevalent among rectal cancer patients. Independent predictor variables of DFT in colon cancer patients were a low level of education, small tumour, ex-smoker, asymptomatic at diagnosis and following the application of screening. Among rectal cancer patients, the corresponding factors were primary school education and being asymptomatic.We conclude that treatment delay in CRC patients is affected not only by clinicopathological factors, but also by sociocultural ones. Greater attention should be paid by the healthcare provider to social groups with less formal education, in order to optimise treatment attentio

Influence of Diagnostic Delay on Survival Rates for Patients with Colorectal Cancer

Colorectal cancer affects men and women alike. Sometimes, due to clinical-pathological factors, the absence of symptoms or the failure to conduct screening tests, its diagnosis may be delayed. However, it has not been conclusively shown that such a delay, especially when attributable to the health system, affects survival. The aim of the present study is to evaluate the overall survival rate of patients with a delayed diagnosis of colorectal cancer. This observational, prospective, multicenter study was conducted at 22 public hospitals located in nine Spanish provinces. For this analysis, 1688 patients with complete information in essential variables were included. The association between diagnostic delay and overall survival at five years, stratified according to tumor location, was estimated by the Kaplan-Meier method. Hazard ratios for this association were estimated using multivariable Cox regression models. The diagnostic delay ≥ 30 days was presented in 944 patients. The presence of a diagnostic delay of more than 30 days was not associated with a worse prognosis, contrary to a delay of less than 30 days (HR: 0.76, 0.64-0.90). In the multivariate analysis, a short delay maintained its predictive value (HR: 0.80, 0.66-0.98) regardless of age, BMI, Charlson index or TNM stage. A diagnostic delay of less than 30 days is an independent factor for short survival in patients with CRC. This association may arise because the clinical management of tumors with severe clinical characteristics and with a poorer prognosis are generally conducted more quickly.This study was supported by public grants from Instituto de Salud Carlos III (PI09/90397, PS09/00314, PS09/00746, PI09/90453, PI09/00910, PI09/90460, PI09/90490, PI13/01692, PI13/00013, PI18/01181, PI18/01589, PS0900805 & PI0900441) and was co-funded by the European Regional Development Fund.S