PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “longitudinal data”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

A quantitative index for evaluating patient care with longitudinal data.

This paper describes a patient-outcome based index of the quality of health care useful to health services researchers and planners. This index is applicable in any health care situation where longitudinal data are available from patients who can be classified into mutually exclusive stages of severity by functional status, psychological well-being or diagnosis and followed over a period of time. The rationale of the index is presented, along with an illustrative example based on a study on long-term care. The procedure for generating weights for the index is briefly described.

Data Collection↗
PubMed1979

A new nonparametric technique for constructing percentiles and normal ranges for growth curves determined from longitudinal data.

A new nonparametric method is proposed for the construction of percentile curves and normal ranges which can be used to classify an individual's growth, velocity, and acceleration of growth dynamically over a time interval selected for its biological importance. Although the procedure requires longitudinal data, it is not necessary that all subjects be measured at identical times. Unlike classic static methods it does not provide percentile curves that are typical of no one. The median curve is the actual curve of the most "central" individual. The method is applicable to growth curves of any form with a general computer program already available for many forms. The technique is demonstrated for growth in weight curves smoothed by high degree polynomials.

Adolescent↗
PubMed1978

Mixed longitudinal data on skeletal age from a group of Dutch children living in Utrecht and surroundings.

The height and weight of 1132 children, aged 8.0--17.0 years studied in 1970--72 in a semi-longitudinal survey in the Dental Institute of Utrecht, are compared with similar data from the national Dutch survey of 1965. Children measured in 1970--72 are somewhat taller than, but have the same weight as, those of the same ages in 1965. The increase in height since 1965 appears to be primarily due to the sub-group enrolled in vocational (as opposed to general) education. The maximal yearly increments in height and weight of the girls occurred between 11.0 and 12.0 years, and between 12.0 and 13.0 years, respectively. For boys the maximal increments in height and weight occurred between 14.0 and 15.0 years. Using the Tanner-Whitehouse 2 method, the skeletal age of this group of children was determined and compared with similar data from British standards. The results of the twenty-bone skeletal age indicated that Dutch boys, and to a lesser extent, girls, mature slightly later than English children at the approximate age range of 10.0--13.0 years and 8.0--10.0 years, respectively. After this age they follow roughly the growth curve of the British standards. The annual increment in skeletal age, plotted with chronological age as a time base, shows a peak for boys as well as girls that coincides with peak height velocity. The Carpal skeletal ages of boys and girls are almost identical in all age-groups with those of the British children, while the RUS skeletal age shows a much greater variability in the different age-groups. The variation in mean velocity (maturity points) between the two populations appears to be more marked in the RUS bones than in the round bones. The TW 1 skeletal age of each subject was plotted against the total TW 2, RUS or Carpal skeletal ages of the same individual. Equations are given for converting TW 1 skeletal ages into total TW 2 or RUS skeletal ages.

Adolescent↗
PubMed1979

A method of presenting longitudinal growth data.

1. Longitudinal growth profiles contain much information but are difficult to incorporate into mathematical and statistical analyses. 2. A growth function, which is a weighted average of growth achievement at different ages, is proposed. 3. This function is a non-dimensional number with defined statistical properties, and emphasizes growth achievement in early life. It can be used to compare the growth of individuals and populations.

Aging↗
PubMed2024

Free-water: A promising structural biomarker for cognitive decline in aging and mild cognitive impairment.

Diffusion MRI derived free-water (FW) metrics show promise in predicting cognitive impairment and decline in aging and Alzheimer's disease (AD). FW is sensitive to subtle changes in brain microstructure, so it is possible these measures may be more sensitive than traditional structural neuroimaging biomarkers. In this study, we examined the associations among FW metrics (measured in the hippocampus and two AD signature meta-ROIs) with cognitive performance, and compared FW findings to those from more traditional neuroimaging biomarkers of AD. We leveraged data from a longitudinal cohort (nparticipants = 296, nobservations = 870, age at baseline: 73 ± 7 years, 40% mild cognitive impairment [MCI]) of older adults who underwent serial neuropsychological assessment (episodic memory, information processing speed, executive function, language, and visuospatial skills) and brain MRI over a maximum of four time points, including baseline (n = 284), 18-month (n = 246), 3-year (n = 215), and 5-year (n = 125) visits. The mean follow-up period was 2.8 ± 1.3 years. Structural MRI was used to quantify hippocampal volume, in addition to Schwarz and McEvoy AD Signatures. FW and FW-corrected fractional anisotropy (FAFWcorr) were quantified in the hippocampus (hippocampal FW) and the AD signature areas (SchwarzFW, McEvoyFW) from diffusion-weighted (dMRI) images using bi-tensor modeling (FW elimination and mapping method). Linear regression assessed the association of each biomarker with baseline cognitive performance. Additionally, linear mixed-effects regression assessed the association between baseline biomarker values and longitudinal cognitive performance. A subsequent competitive model analysis was conducted on both baseline and longitudinal data to determine how much additional variance in cognitive performance was explained by each biomarker compared to the covariate only model, which included age, sex, race/ethnicity, apolipoprotein-ε4 status, cognitive status, and modified Framingham Stroke Risk Profile scores. All analyses were corrected for multiple comparisons using an FDR procedure. Cross-sectional results indicate that hippocampal volume, hippocampal FW, Schwarz and McEvoy AD Signatures, and the SchwarzFW and McEvoyFW metrics are all significantly associated with memory performance. Baseline competitive model analyses showed that the McEvoy AD Signature and SchwarzFW explain the most unique variance beyond covariates for memory (ΔRadj 2 = 3.47 ± 1.65%) and executive function (ΔRadj 2 = 2.43 ± 1.63%), respectively. Longitudinal models revealed that hippocampal FW explained substantial unique variance for memory performance (ΔRadj 2 = 8.13 ± 1.25%), and outperformed all other biomarkers examined in predicting memory decline (pFDR = 1.95 x 10-11). This study shows that hippocampal FW is a sensitive biomarker for cognitive impairment and decline, and provides strong evidence for further exploration of this measure in aging and AD.

Alzheimer’s disease (AD)↗
PubMed1979

Perinatal mortality by birth order within cohorts based on sibship size.

Cross-sectional surveys of perinatal mortality show a U-shaped curve when plotted against parity, implying that fourth and subsequent babies are at increased risk. Our study of a large, population-based longitudinal data set shows that this result is an artefact and that perinatal mortality falls with increasing parity. Within cohorts of mothers based on attained sibship size the perinatal mortality decreases with increasing parity and increases with sibship size. These associations, which are not noticeably affected by maternal age, ssem in part to operate through an association between parity, sibship size, and birth weight. This analysis shows the importance of using longitudinal data in analysing such relations.

Birth Order↗
PubMed1978

Prediction of the mesiodistal widths of maxillary permanent canines and premolars.

Multiple regression equations for prediction of the mesiodistal widths of the maxillary canines and premolars were developed for the right and left sides of the arches of males and females. The equations were developed from longitudinal data taken from ninety-two Caucasian children (forty-six boys and forty-six girls) who participated in the Iowa Growth Study. The multiple regression equations, when compared with three currently used methods of prediction, were the best predictors. The newly developed equations and other prediction methods currently in use were tested on longitudinal data taken from a sample of forty-three Caucasian orthodontic patients (sixteen males and twenty-seven females). Again, the multiple regression equations had the best performance.

Adolescent↗
PubMed2026

Early and late CTCAE and patient-reported outcomes following lung cancer radiotherapy: A sex-stratified descriptive analysis from the REQUITE cohort.

BACKGROUND: Long-term prospective data on lung cancer patients treated with radiotherapy are limited, restricting understanding of outcomes and sex-specific characteristics. The multicentre REQUITE study provides standardized follow-up data from an international cohort. METHODS: We analysed longitudinal data from 530 lung cancer patients treated with radical radiotherapy (sequential or concurrent chemoradiotherapy, or stereotactic body radiation therapy [SBRT]) between 2014 and 2017 at 16 centres in Europe and the USA. Healthcare professionals prospectively recorded 21 pulmonary, oesophageal, neurological, cardiac, and skin adverse events using CTCAE v4.0. Patient-reported outcomes assessed symptoms, quality-of-life, fatigue, and physical activity. Adverse event incidence was stratified by sex, radiotherapy technique, chemotherapy administration, smoking status, and other clinical factors. RESULTS: At 12 months, 309 patients were evaluable, with 151 having follow-up beyond one year. Pulmonary adverse events were most frequent (40% grade ≥ 2), mainly dyspnoea and cough. Women had higher rates of oesophagitis, and more frequently reported dysphagia, and chest wall pain, while men experienced a higher frequency of cardiac adverse events. Exploratory subgroup analyses identified significant sex-related differences in grade ≥ 3 pulmonary adverse events following SBRT and in overall grade ≥ 2 oesophageal adverse events among patients with clinical stage I-II and those aged >70 years. Patient-reported outcomes showed persistent fatigue and reduced physical activity, particularly in females. Symptom prevalence and severity varied by sex, age, treatment modality, smoking status, and clinical stage. CONCLUSION: The REQUITE-Lung cohort provides prospectively collected real-world data on radiotherapy-related adverse events in lung cancer patients. This study describes patterns of adverse events and patient-reported outcomes according to sex, age, and treatment characteristics. These findings are hypothesis-generating and may support future validation in independent and pooled datasets.

Patient-reported outcomes↗
PubMed2026

Mortality of Individuals With PRNP Variants Associated With Prion Disease in the United States, 1998-2024.

BACKGROUND AND OBJECTIVES: To characterize the survival of individuals with pathogenic PRNP variants-including to estimate annual hazards, to judge the accuracy of previously reported survival data, and to evaluate the utility of public record searches in determining vital status. METHODS: In this single-center cohort study, we gathered data on individuals who received positive antemortem PRNP genetic tests at the US National Prion Disease Pathology Surveillance Center (NPDPSC), including both diagnostic tests in symptomatic individuals, and predictive tests in asymptomatic individuals. Genetic test and autopsy results were queried from the NPDPSC database, and public record searches were conducted using online tools. RESULTS: Four hundred four individuals received positive genetic test results. Of 206 cases symptomatic at the time of genetic testing, 188 are likely now deceased based on typical disease duration for their genetic variants. Combined autopsy and public record searches in combination confirmed 174 of these deaths, for an estimated 92.6% sensitivity. We evaluated the age-dependent penetrance of the reportedly highly penetrance variants D178N and E200K and the reportedly low-penetrance variant V210I. Among 99 initially asymptomatic individuals with the pathogenic E200K variant, more than 936 person-years of follow-up, 18 deaths were observed, significantly fewer than 27.4 expected according to life tables based on retrospective data. The age-dependent penetrance of E200K calculated from these longitudinal data was significantly lower than that from retrospective data, with 69% penetrance by age 80 and a median age at death of 75. For the pathogenic D178N variant, the median age at death was 57, which was numerically later, but not significantly different from, that seen in retrospective data. For V210I, just 2 deaths occurred, both after age 90, consistent with minimal penetrance. DISCUSSION: Our data support high penetrance of PRNP D178N and E200K variants and low penetrance of V210I. For E200K, the age at onset distribution appears to be shifted slightly later, and lifetime risk slightly lower, than previously reported. Autopsy data and public death records in combination were sensitive and concordant for determining long-term outcomes, but additional prospective data should be gathered to support future preventive trials.

Journal Article↗
PubMed2025

Clinical and genetic variant re-analysis among pediatric probands undergoing genetic testing for arrhythmia syndromes.

BACKGROUND: Despite increases in genetic testing, longitudinal data regarding changes in diagnostic yield and variant reclassification for inherited arrhythmia syndromes are limited. OBJECTIVE: Determine longitudinal changes in diagnostic yield and variant classification. METHODS: Single-center retrospective study of probands <18 years undergoing genetic testing for suspected inherited cardiac conditions associated with arrhythmias, 2007 to 2018. Variants were classified as diagnostic (pathogenic/likely pathogenic), non-diagnostic (benign/likely benign [B/LB]), or variants of uncertain significance (VUS). Variant reclassification was performed in October 2023 using VarSome and American College of Medical Genetics criteria. We evaluated results by era (early 2007-2013 vs. later 2014-2018, coinciding with Sanger and next-generation sequencing, respectively) and by likelihood of disease based on clinical evaluation. RESULTS: Of 306 probands, initial testing was 23.2% diagnostic, 55.6% non-diagnostic (33.7% no variant, 21.9% B/LB), and 21.2% VUS. When comparing eras, diagnostic yield decreased (34.1%-15.3%), VUS increased (9.3%-29.9%), and non-diagnostic remained similar (55% to 57%). Variants for 22.7% (46/203) of probands with &#x2265;1 variant changed: 9.9% of diagnostic variants (7/71) downgraded to VUS or non-diagnostic, and 60.0% of VUS changed (23.1% upgraded, 36.9% downgraded). B/LB variants did not change. Probands with higher disease likelihood had 6-times the odds of diagnostic results compared to lower disease likelihood, regardless of era (odds ratio 6.3, 95% confidence interval 3.2-12.4, P < .0001). CONCLUSION: Variant reclassification led to changes in 23% of probands, both downgrading and upgrading status, even among probands initially thought to be pathogenic. When comparing later to earlier eras, VUS variants increased while diagnostic yield decreased. Findings support the need for variant re-interpretation and periodic reclassification over time.

Humans↗
PubMed1975

Prediction of adult height from height, bone age, and occurrence of menarche, at ages 4 to 16 with allowance for midparent height.

Multiple regression equations for predicting the adult height of boys and girls from height and bone age at ages 4 and upwards are presented. There is a separate equation for each half year of chronological age; and for pre- and postmenarcheal girls at ages 11 to 14. These are based on longitudinal data from 116 boys and 95 girls of the Harpenden Growth Study and the London group of the International Children's Centre longitudinal study. The bone age used is the revised version of the Tanner-Whitehouse standards, omitting the score for carpal bones (RUS age, TW 2 system). Boys aged 4 to 12 are predicted in 95% of instances to within plus or minus 7 cm of true height, and at ages 13 and 14 to within plus or minus 6 cm. Girls ages 4 to 11 are predicted to within plus or minus 6 cm; premenarcheal girls aged 12 and 13 to within plus or minus 5 and plus or minus 4 cm, respectively; and postmenarcheal girls aged 12 and 13 to within plus or minus 4 and plus or minus 3 cm, respectively. Prediction can be somewhat imporved by allowing for midparent height. One-third of the amount that midparent height differs from mean midparent height is added or subtracted. An alternative system of equations which are based on initial classification by bone age rather than chronological age is given. These have about the same accuracy as the equations based on initial classification by chronological age, but allowance for bone age retardation is less. It is not clear which system is preferable. The equations probably apply to girls complaining of tall stature and boys or girls complaining of shortness and needing reassurance as to normality. In clearly pathological children, such as those with endocrinopathies, they do not apply.

Adolescent↗
PubMed1979

Aspects of phonological acquisition during articulation training.

Acquisition of correct /s/ over time was studied in five misarticulating children and compared to data reported for younger children during normal phonological development. Changes in production of /s/ as the children were learning to produce /s/ were examined in untrained syllables session by session. These longitudinal data were explored for patterns reported to occur in normal acquisition. It was found that the misarticulating children typically shifted their responses from correct to incorrect during the acquisition period; this may be attributed to competing rules operating during the early stages of acquisition similar to the rules proposed to be operating during morphological acquisition. The children varied in the time required to acquire correct production which is comparable to the variability reported in normal acquisition. Individual learning strategies were noted in the children's productions of consonant clusters which correspond to the proposed stages of development in normal phonological acquisition.

Articulation Disorders↗
PubMed2026

Beyond Morphology: Reframing Lymph-Node Metastasis Prediction Through Clonal Ecology-Decades-Long Genomic Instability and Polyclonal-to-Monoclonal Transitions as the Missing Dimension in Cancer.

Recent whole-genome, lineage-tracing, single-cell, and spatial studies have reshaped our understanding of tumor evolution, revealing that cancers can arise from polyclonal populations, undergo decades-long genomic instability before clinical detection, and progress through dynamic changes in subclonal composition, cellular state, and ecological organization. These findings challenge the assumption underlying morphology-based prediction models that metastatic risk can be inferred from static histological features alone. Here, we revisit lymph-node metastasis prediction in colorectal cancer through clonal ecology, integrating computational pathology with evolutionary oncology. Drawing on the subclonal switchboard model proposed in 2012 and subsequent artificial intelligence (AI)-enabled approaches for tracking dominant and dormant subclones, we synthesize evidence that metastatic potential reflects clonal ancestry, evolutionary timing, spatial niche architecture, cellular plasticity, intercellular interactions, dormancy, and treatment-driven shifts in subclonal fitness. We define five complementary methodological pillars for operationalizing clonal ecology: single-cell transcriptomics for resolving rare subclones, evolutionary trajectories, and adaptive cell states; lineage tracing and phylogenetics for reconstructing clonal ancestry and divergence; spatial transcriptomics and genomics for mapping subclonal geography and tumor-stromal-immune interactions; longitudinal liquid biopsy surveillance for monitoring residual disease, clonal turnover, and emerging resistance; and AI-enabled multimodal integration for connecting histopathology, genomics, spatial biology, and longitudinal data into predictive ecological-state models. Multiple-instance learning and pathology foundation models provide scalable computational foundations for evolution-aware prediction. Translationally, dormant subclones represent actionable reservoirs of recurrence. A longitudinal clinical and experimental study of KMT2A-rearranged acute myeloid leukemia further supports central predictions of the subclonal switchboard framework by demonstrating treatment-associated shifts in subclonal dominance, persistence of cryptic adaptive programs, and ecological rewiring during resistance and relapse. We propose clonal ecology as a measurable dimension for extending morphology-driven prediction toward integrative models that anticipate evolutionary transitions, identify therapeutic windows, and proactively constrain adaptive tumor ecosystems before resistant or metastatic subclones achieve clinical dominance.

Humans↗
PubMed1978

Early septal surgery in a chimpanzee animal model.

Early resection of the proximal one-third of the cartilagenous nasal septum was performed in a chimpanzee. Longitudinal data on facial growth was collected for fourteen months. Growth rates (from regression equations) were shown to be the same for operated and unoperated animals. Implications for cleft palate repair are discussed.

Age Factors↗
PubMed2025

Prevalence and predictors of low bone mineral density in pediatric inflammatory bowel disease.

OBJECTIVES: Bone health is at risk in children with inflammatory bowel disease (IBD). This study examined the prevalence and predictors of low bone mineral density (BMD) in a cohort of children and young adults with IBD. METHODS: This single-center retrospective study included patients with IBD, ages 3.5-22 years, with completed dual x-ray absorptiometry (DXA) scans from 2006 to 2019. Demographic, clinical, and laboratory data were collected. Logistic regression analysis identified predictors associated with low BMD (Z-scores&#x2009;&#x2264;&#x2009;-2 standard deviations [SDs]) for three outcomes. In an overlapping IBD cohort with available genetic data between 2002 and 2019 (n&#x2009;=&#x2009;378), genetic risk for diminished bone health was calculated using published polygenic risk scores generated from genome-wide association studies based on DXA or heel ultrasound speed of sound (SOS). Linear regression analysis examined associations of low BMD and genetic risk. RESULTS: Low BMD prevalence was 7% in our cohort (n&#x2009;=&#x2009;600) based on spine bone mineral apparent density (BMAD), which best accounts for growth delays. Median (interquartile range [IQR]) spine BMAD Z-score was -0.37&#x2009;SD (-1.11 to 0.35). Predictors of low BMAD included lower BMI Z-score (odds ratio [OR]: 0.67, p value: 0.02) and decreased height Z-score (OR: 0.6, p value: 0.005). Of those with longitudinal data (n&#x2009;=&#x2009;118), low BMI (OR: 0.44, p value: <0.001) and steroid use (OR: 3.42, p value: 0.01) were associated with suboptimal bone health (Z-scores&#x2009;&#x2264;&#x2009;-1SD). In the cohort with genetic data, heel genomic SOS (&#x3b2; [standard error] = 0.17 [0.35], p&#x2009;&#x2264;&#x2009;0.01) was associated with BMD. CONCLUSIONS: Lower BMI should prompt DXA monitoring in pediatric IBD. Genetic predisposition may identify an at-risk subpopulation.

Humans↗
PubMed1979

Cognitive speed and subsequent intellectual development: a longitudinal investigation.

The hypothesis that a measure of intellectual speed assessed at one point in time would predict intellectual achievement at a later point in time was evaluated with a time-lagged cross-correlational analysis, an application of causal modeling techniques. Longitudinal data for 32 males and females, tested in 1944 (mean age 19.5 years) and in 1972 (mean age 46.7 years), supported the hypothesized relationships with an associated p less than .01. The Relations Factor of the Army Alpha Examination--consisting of scores from a highly speeded simple analogies test and a short-term memory test--administered at age 20 was highly predictive of both verbal and numerical ability in middle age. The results highlight the cognitive intellectual aspect of the speed of behavior. In addition, these findings supplement Hunt's studies of the relationships between speed of cognitive processing and psychometric abilities in young adults, and emphasize the importance of cognitive speed for subsequent intellectual development. Implications for the intellectual speed hypothesis of Birren and the utilization of time-lag designs in longitudinal research are discussed.

Adult↗