BackgroundThe minimum clinically important difference (MCID) is used to interpret the clinical relevance of results reported by trials and meta-analyses as well as to plan sample sizes in new studies. However, there is a lack of consensus about the size of MCID in acute pain, which is a core symptom affecting patients across many clinical conditions.MethodsWe identified and systematically reviewed empirical studies of MCID in acute pain. We searched PubMed, EMBASE and Cochrane Library, and included prospective studies determining MCID using a patient-reported anchor and a one-dimensional pain scale (e.g. 100 mm visual analogue scale). We summarised results and explored reasons for heterogeneity applying meta-regression, subgroup analyses and individual patient data meta-analyses.ResultsWe included 37 studies (8479 patients). Thirty-five studies used a mean change approach, i.e. MCID was assessed as the mean difference in pain score among patients who reported a minimum degree of improvement, while seven studies used a threshold approach, i.e. MCID was assessed as the threshold in pain reduction associated with the best accuracy (sensitivity and specificity) for identifying improved patients. Meta-analyses found considerable heterogeneity between studies (absolute MCID: I2 = 93%, relative MCID: I2 = 75%) and results were therefore presented qualitatively, while analyses focused on exploring reasons for heterogeneity. The reported absolute MCID values ranged widely from 8 to 40 mm (standardised to a 100 mm scale) and the relative MCID values from 13% to 85%. From analyses of individual patient data (seven studies, 918 patients), we found baseline pain strongly associated with absolute, but not relative, MCID as patients with higher baseline pain needed larger pain reduction to perceive relief. Subgroup analyses showed that the definition of improved patients (one or several categories improvement or meaningful change) and the design of studies (single or multiple measurements) also influenced MCID values.ConclusionsThe MCID in acute pain varied greatly between studies and was influenced by baseline pain, definitions of improved patients and study design. MCID is context-specific and potentially misguiding if determined, applied or interpreted inappropriately. Explicit and conscientious reflections on the choice of a reference value are required when using MCID to classify research results as clinically important or trivial.

Hypertension may be the most significant cardiovascular risk factor. Few studies have assessed the prognostic value of echocardiography in hypertensive individuals. This study examines the incremental prognostic value of adding echocardiographic parameters to established risk factors in individuals from the general population with and without hypertension. A total of 1294 individuals from the general population underwent a health examination and an echocardiogram including 2-dimensional speckle tracking. Outcome was a composite of ischemic heart disease and heart failure. The prevalence of hypertension was 38.3%. During a median follow-up of 12.5 years (interquartile range, 9.4-12.8 years), 222 participants (17.2%) developed the outcome. Out of these 222 events, 145 (65%) occurred in hypertensive participants, whereas 77 (35%) occurred in nonhypertensive individuals, corresponding to an incidence rate of 32/(1000×person-years) and 8/(1000×person-years), respectively. Follow-up was 100%. After multivariable adjustment, only left ventricular mass index predicted the outcome in hypertensive individuals, whereas only global longitudinal strain predicted the outcome in nonhypertensive individuals. In hypertensive individuals the prognostic value of left ventricular mass index was incremental to SCORE and abnormal ECG status. In nonhypertensive individuals the prognostic value of global longitudinal strain was incremental to SCORE and abnormal ECG status. The prognostic value of echocardiography in predicting cardiovascular outcomes in the general population is altered by hypertension. In hypertensive individuals, left ventricular mass index added incremental prognostic value in addition to established risk factors. In nonhypertensive individuals, global longitudinal strain added incremental prognostic value in addition to established risk factors.

BACKGROUND The relative vaccine effectiveness (rVE) of high-dose quadrivalent influenza vaccines (QIV-HD) versus standard-dose quadrivalent influenza vaccines (QIV-SD) against hospitalizations and mortality in the general older population has not been evaluated in an individually randomized trial. Because of the large sample size required, such a trial will need to incorporate innovative, pragmatic elements. METHODSWe conducted a pragmatic, open-label, active-controlled, randomized feasibility trial in Danish citizens aged 65 to 79 years during the 2021-2022 influenza season. Participants were randomly assigned 1:1 to receive QIV-HD or QIV-SD. Randomization was integrated into routine vaccination practice, and the trial relied solely on nationwide administrative health registries for data collection. Outcomes consisted of a feasibility assessment and descriptive rVE estimates. RESULTSWe invited 34,000 persons to participate. A total of 12,477 randomly assigned participants were included in the final analyses. Mean (-SD) age was 71.7-3.9 years, and 5877 (47.1%) were women. Registry-based data collection was feasible, with complete follow-up data for 99.9% of participants. Baseline characteristics were comparable to those of the overall Danish population aged 65 to 79 years. The incidence of hospitalization for influenza or pneumonia was 10 (0.2%) of 6245 in the QIV-HD group and 28 (0.4%) of 6232 in the QIV-SD group (rVE, 64.4%; 95% confidence interval, 24.4 to 84.6). All-cause death occurred in 21 (0.3%) and 41 (0.7%) participants in the QIV-HD and QIV-SD groups, respectively (rVE, 48.9%; 95% confidence interval, 11.5 to 71.3).CONCLUSIONS Conducting a pragmatic randomized trial of QIV-HD versus QIV-SD using existing infrastructure and registry-based data collection was feasible. The findings of lower incidence of hospitalization for influenza or pneumonia and all-cause mortality inThe author affiliations are listed at the end of the article.