Browsing by Subject "Prediction"

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  • Balla, Viktória Roxána; Szalóki, Szilvia; Kilencz, Tünde; Dalos, Vera Daniella; Németh, Roland; Csifcsák, Gábor (2020)
    The association between an action and its sensory consequence has been linked to our sense of agency (SoA). While ecological validity is crucial in investigating such a complex phenomenon, previous paradigms focusing on the cortical analysis of movement-related images used simplified experimental protocols. Here, we examined the influence of action-associated predictive processes on visual event-related potentials (ERPs) in a paradigm that models everyday actions more precisely, using a commercial gesture control device, ecological stimuli depicting a human hand and a behavioural training to reinforce the sense of control over action outcomes. We assessed whether a more natural setup would result in robust ERP modifications following self-initiated movements relative to passive viewing of the same images. We found no compelling evidence for amplitude modulation for the early occipital C1 and P1 components. Crucially, we observed strong action-associated amplitude enhancement for the posterior N1, an effect that was not present in our previous study that relied on conventional button-presses. We propose that the N1 effect in our ecologically more valid paradigm can either reflect stronger attentional amplification of domain-specific visual processes following self-initiated actions, or indicate that sensory predictions in the visual N1 latency range manifest in larger (rather than reduced) ERPs. Overall, our novel approach utilizing a gesture-control device can be a potent tool for investigating the behavioural and neural manifestations of SoA in the visual modality.
  • Wirtz, Ralph M.; Sihto, Harri; Isola, Jorma; Heikkila, Paivi; Kellokumpu-Lehtinen, Pirkko-Liisa; Auvinen, Paivi; Turpeenniemi-Hujanen, Taina; Jyrkkio, Sirkku; Lakis, Sotiris; Schlombs, Kornelia; Laible, Mark; Weber, Stefan; Eidt, Sebastian; Sahin, Ugur; Joensuu, Heikki (2016)
    The biological subtype of breast cancer influences the selection of systemic therapy. Distinction between luminal A and B cancers depends on consistent assessment of Ki-67, but substantial intra-observer and inter-observer variability exists when immunohistochemistry (IHC) is used. We compared RT-qPCR with IHC in the assessment of Ki-67 and other standard factors used in breast cancer subtyping. RNA was extracted from archival breast tumour tissue of 769 women randomly assigned to the FinHer trial. Cancer ESR1, PGR, ERBB2 and MKI67 mRNA content was quantitated with an RT-qPCR assay. Local pathologists assessed ER, PgR and Ki-67 expression using IHC. HER2 amplification was identified with chromogenic in situ hybridization (CISH) centrally. The results were correlated with distant disease-free survival (DDFS) and overall survival (OS). qPCR-based and IHC-based assessments of ER and PgR showed good concordance. Both low tumour MKI67 mRNA (RT-qPCR) and Ki-67 protein (IHC) levels were prognostic for favourable DDFS [hazard ratio (HR) 0.42, 95 % CI 0.25-0.71, P = 0.001; and HR 0.56, 0.37-0.84, P = 0.005, respectively] and OS. In multivariable analyses, cancer MKI67 mRNA content had independent influence on DDFS (adjusted HR 0.51, 95 % CI 0.29-0.89, P = 0.019) while Ki-67 protein expression had not any influence (P = 0.266) whereas both assessments influenced independently OS. Luminal B patients treated with docetaxel-FEC had more favourable DDFS and OS than those treated with vinorelbine-FEC when the subtype was defined by RT-qPCR (for DDFS, HR 0.52, 95 % CI 0.29-0.94, P = 0.031), but not when defined using IHC. Breast cancer subtypes approximated with RT-qPCR and IHC show good concordance, but cancer MKI67 mRNA content correlated slightly better with DDFS than Ki-67 expression. The findings based on MKI67 mRNA content suggest that patients with luminal B cancer benefit more from docetaxel-FEC than from vinorelbine-FEC.
  • Pöllänen, Petra (Helsingfors universitet, 2016)
    Aims/hypothesis To characterise rapid progressors to type 1 diabetes among children recruited from the general population based on HLA-conferred disease susceptibility. Methods We observed 7410 HLA-predisposed children participating in the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Study from birth for development of beta cell autoimmunity and type 1 diabetes over a median follow-up time of 16.2 (range 0.9-21.1) years. Islet cell antibodies, and autoantibodies to insulin (IAA), GAD (GADA), and islet antigen 2 (IA-2A) were analysed as markers of beta cell autoimmunity. Rapid progression was defined as progression to clinical type 1 diabetes within 1.5 years after autoantibody seroconversion. We analysed the association between rapid progression and demographic and autoantibody characteristics as well as genetic markers including 25 non-HLA single nucleotide polymorphisms (SNPs) predisposing to type 1 diabetes. Results Altogether 1645 children (22%) tested positive for at least one diabetes-associated autoantibody, and 248 (15%) of the seroconverters progressed to type 1 diabetes by the end of 2015. The median time from seroconversion to diagnosis was 0.51 years in rapid progressors (n=42, 17%), and 5.4 years in slower progressors. Rapid progression was observed both among young and early pubertal children. Compared to slower progressors, rapid progressors had higher frequency of multipositivity, higher titres of ICA, IAA, and IA-2A at seroconversion, and higher prevalence of the secretor genotype in the FUT2 gene. Compared to autoantibody-positive non-progressors, rapid progressors were younger, carried more often the high-risk HLA genotype, the FUT2 secretor genotype, and a predisposing SNP in the PTPN22 gene, had higher frequency of ICA, IAA, GADA, IA-2A, and multipositivity, and higher titres of all four autoantibodies at seroconversion. Conclusions At seroconversion, individuals with rapid progression to type 1 diabetes are characterised by young age, higher autoantibody titres, positivity for multiple autoantibodies, and higher prevalence of a FUT2 SNP. The double-peak profile of seroconversion age among the rapid progressors demonstrates for the first time that rapid progression may take place not only in young children, but also in children in early puberty. Rapid progressors might benefit from careful clinical follow-up and early preventive measures.
  • Pollanen, Petra M.; Lempainen, Johanna; Laine, Antti-Pekka; Toppari, Jorma; Veijola, Riitta; Vahasalo, Paula; Ilonen, Jorma; Siljander, Heli; Knip, Mikael (2017)
    Aims/hypothesis In this study, we aimed to characterise rapid progressors to type 1 diabetes among children recruited from the general population, on the basis of HLA-conferred disease susceptibility. Methods We monitored 7410 HLA-predisposed children participating in the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study for the development of beta cell autoimmunity and type 1 diabetes from birth over a median follow-up time of 16.2 years (range 0.9-21.1 years). Islet cell antibodies (ICA) and autoantibodies to insulin (IAA), GAD (GADA) and islet antigen 2 (IA-2A) were assessed as markers of beta cell autoimmunity. Rapid progression was defined as progression to clinical type 1 diabetes within 1.5 years of autoantibody seroconversion. We analysed the association between rapid progression and demographic and autoantibody characteristics as well as genetic markers, including 25 non-HLA SNPs predisposing to type 1 diabetes. Results Altogether, 1550 children (21%) tested positive for at least one diabetes-associated autoantibody in at least two samples, and 248 (16%) of seroconverters progressed to type 1 diabetes by the end of 2015. The median time from seroconversion to diagnosis was 0.51 years in rapid progressors (n = 42, 17%) and 5.4 years in slower progressors. Rapid progression was observed both among young (<5 years) and early pubertal children (> 7 years), resulting in a double-peak distribution of seroconversion age. Compared with slower progressors, rapid progressors had a higher frequency of positivity for multiple (>= 2) autoantibodies and had higher titres of ICA, IAA and IA-2A at seroconversion, and there was a higher prevalence of the secretor genotype in the FUT2 gene among those carrying the high-risk HLA genotype. Compared with autoantibody-positive non-progressors, rapid progressors were younger, were more likely to carry the high-risk HLA genotype and a predisposing SNP in the PTPN22 gene, had higher frequency of ICA, IAA, GADA and IA-2A positivity and multipositivity, and had higher titres of all four autoantibodies at seroconversion. Conclusions/interpretation At seroconversion, individuals with rapid progression to type 1 diabetes were characterised by a younger age, higher autoantibody titres, positivity for multiple autoantibodies and higher prevalence of a FUT2 SNP. The double-peak profile for seroconversion age among the rapid progressors demonstrates for the first time that rapid progression may take place not only in young children but also in children in early puberty. Rapid progressors might benefit from careful clinical follow-up and early preventive measures.
  • Kytö, Elina; Bult, Harold; Aarts, Esther; Wegman, Joost; Ruijschop, Rianne MAJ; Mustonen, Sari (2019)
    In this study, we aimed to investigate the relation between consumer purchases of three branded blueberry flavored quarks and respective responses of the same consumers to these products using 1) traditional explicit consumer surveys measuring verbalized impressions, 2) novel explicit pictorial emoji scores and 3) implicit behavioral responses produced during an approach-avoidance task (AAT). Explicit measures (n=134) were collected before product tasting (expectation condition) during an online survey, and after product tasting (perception condition) during a Central Location Test (CLT). Implicit measures were collected with a subset of 56 randomly selected subjects during the CLT. These included electroencephalographic (EEG) measures, joystick response speed and pupil size responses. During one month following the CLT, respondents registered their purchases via an online diary. Bivariate correlations indicated that explicit scores correlate better with product purchase amounts in the perception condition than in the expectation condition. Furthermore, verbalized ratings correlated better with product purchase amounts than pictorial emoji scores. Of the implicit responses, EEG responses produced the strongest correlations with purchase behavior, similar to those observed for verbalized explicit ratings in the expectation condition. Multiple linear regression modelling indicated that the best-fitting model consisted of an emoji score, purchase intention score, pleasantness score, brand relationship score, and implicit joystick response speed. Overall, purchase behavior was associated stronger with explicit responses than with implicit responses. Yet, the prominent role of implicit joystick response speed in the multivariate regression model suggests its unique contribution to the understanding of purchase behavior.
  • Alabi, Rasheed Omobolaji; Elmusrati, Mohammed; Sawazaki-Calone, Iris; Kowalski, Luiz Paulo; Haglund, Caj; Coletta, Ricardo D.; Mäkitie, Antti A.; Salo, Tuula; Almangush, Alhadi; Leivo, Ilmo (2020)
    Background: The proper estimate of the risk of recurrences in early-stage oral tongue squamous cell carcinoma (OTSCC) is mandatory for individual treatment-decision making. However, this remains a challenge even for experienced multidisciplinary centers. Objectives: We compared the performance of four machine learning (ML) algorithms for predicting the risk of locoregional recurrences in patients with OTSCC. These algorithms were Support Vector Machine (SVM), Naive Bayes (NB), Boosted Decision Tree (BDT), and Decision Forest (DF). Materials and methods: The study cohort comprised 311 cases from the five University Hospitals in Finland and A.C. Camargo Cancer Center, Sao Paulo, Brazil. For comparison of the algorithms, we used the harmonic mean of precision and recall called F1 score, specificity, and accuracy values. These algorithms and their corresponding permutation feature importance (PFI) with the input parameters were externally tested on 59 new cases. Furthermore, we compared the performance of the algorithm that showed the highest prediction accuracy with the prognostic significance of depth of invasion (DOI). Results: The results showed that the average specificity of all the algorithms was 71% The SVM showed an accuracy of 68% and F1 score of 0.63, NB an accuracy of 70% and F1 score of 0.64, BDT an accuracy of 81% and F1 score of 0.78, and DF an accuracy of 78% and F1 score of 0.70. Additionally, these algorithms outperformed the DOI-based approach, which gave an accuracy of 63%. With PFI-analysis, there was no significant difference in the overall accuracies of three of the algorithms; PFI-BDT accuracy increased to 83.1%, PFI-DF increased to 80%, PFI-SVM decreased to 64.4%, while PFI-NB accuracy increased significantly to 81.4%. Conclusions: Our findings show that the best classification accuracy was achieved with the boosted decision tree algorithm. Additionally, these algorithms outperformed the DOI-based approach. Furthermore, with few parameters identified in the PFI analysis, ML technique still showed the ability to predict locoregional recurrence. The application of boosted decision tree machine learning algorithm can stratify OTSCC patients and thus aid in their individual treatment planning.
  • Ma, Yihan; Sun, Hua; Chen, Yang; Zhang, Jiayun; Xu, Yang; Wang, Xin; Hui, Pan (2021)
    Online lodging platforms have become more and more popular around the world. To make a booking in these platforms, a user usually needs to select a city first, then browses among all the prospective options. To improve the user experience, understanding the zone preferences of a user's booking behavior will be helpful. In this work, we aim to predict the zone preferences of users when booking accommodations for the next travel. We have two main challenges: (1) The previous works about next information of Points Of Interest (Pals) recommendation are mainly focused on users' historical records in the same city, while in practice, the historical records of a user in the same city would be very sparse. (2) Since each city has its own specific geographical entities, it is hard to extract the structured geographical features of accommodation in different cities. Towards the difficulties, we propose DeepPredict, a zone preference prediction system. To tackle the first challenge, DeepPredict involves users' historical records in all the cities and uses a deep learning based method to process them. For the second challenge, DeepPredict uses HERE places API to get the information of pals nearby, and processes the information with a unified way to get it. Also, the description of each accommodation might include some useful information, thus we use Sent2Vec, a sentence embedding algorithm, to get the embedding of accommodation description. Using a real-world dataset collected from Airbnb, DeepPredict can predict the zone preferences of users' next bookings with a remarkable performance. DeepPredict outperforms the state-of-the-art algorithms by 60% in macro Fl-score.
  • Li, Ling-Jun; Wang, Ximeng; Chong, Yap Seng; Chan, Jerry Kok Yen; Tan, Kok Hian; Eriksson, Johan G.; Huang, Zhongwei; Rahman, Mohammad L.; Cui, Liang; Zhang, Cuilin (2023)
    BackgroundMetabolomic changes during pregnancy have been suggested to underlie the etiology of gestational diabetes mellitus (GDM). However, research on metabolites during preconception is lacking. Therefore, this study aimed to investigate distinctive metabolites during the preconception phase between GDM and non-GDM controls in a nested case-control study in Singapore.MethodsWithin a Singapore preconception cohort, we included 33 Chinese pregnant women diagnosed with GDM according to the IADPSG criteria between 24 and 28 weeks of gestation. We then matched them with 33 non-GDM Chinese women by age and pre-pregnancy body mass index (ppBMI) within the same cohort. We performed a non-targeted metabolomics approach using fasting serum samples collected within 12 months prior to conception. We used generalized linear mixed model to identify metabolites associated with GDM at preconception after adjusting for maternal age and ppBMI. After annotation and multiple testing, we explored the additional predictive value of novel signatures of preconception metabolites in terms of GDM diagnosis.ResultsA total of 57 metabolites were significantly associated with GDM, and eight phosphatidylethanolamines were annotated using HMDB. After multiple testing corrections and sensitivity analysis, phosphatidylethanolamines 36:4 (mean difference beta: 0.07; 95% CI: 0.02, 0.11) and 38:6 (beta: 0.06; 0.004, 0.11) remained significantly higher in GDM subjects, compared with non-GDM controls. With all preconception signals of phosphatidylethanolamines in addition to traditional risk factors (e.g., maternal age and ppBMI), the predictive value measured by area under the curve (AUC) increased from 0.620 to 0.843.ConclusionsOur data identified distinctive signatures of GDM-associated preconception phosphatidylethanolamines, which is of potential value to understand the etiology of GDM as early as in the preconception phase. Future studies with larger sample sizes among alternative populations are warranted to validate the associations of these signatures of metabolites and their predictive value in GDM.
  • Saunders, Gretchen R. B.; Wang, Xingyan; Chen, Fang; Jang, Seon-Kyeong; Liu, Mengzhen; Wang, Chen; Gao, Shuang; Jiang, Yu; Khunsriraksakul, Chachrit; Otto, Jacqueline M.; Addison, Clifton; Akiyama, Masato; Albert, Christine M.; Aliev, Fazil; Alonso, Alvaro; Arnett, Donna K.; Ashley-Koch, Allison E.; Ashrani, Aneel A.; Barnes, Kathleen C.; Barr, R. Graham; Bartz, Traci M.; Becker, Diane M.; Bielak, Lawrence F.; Benjamin, Emelia J.; Bis, Joshua C.; Bjornsdottir, Gyda; Blangero, John; Bleecker, Eugene R.; Boardman, Jason D.; Boerwinkle, Eric; Boomsma, Dorret; Boorgula, Meher Preethi; Bowden, Donald W.; Brody, Jennifer A.; Cade, Brian E.; Chasman, Daniel; Chavan, Sameer; Chen, Yii-Der Ida; Chen, Zhengming; Cheng, Iona; Cho, Michael H.; Choquet, Helene; Cole, John W.; Cornelis, Marilyn C.; Cucca, Francesco; Curran, Joanne E.; de Andrade, Mariza; Dick, Danielle M.; Docherty, Anna R.; Duggirala, Ravindranath; Eaton, Charles B.; Ehringer, Marissa A.; Esko, Tonu; Faul, Jessica D.; Silva, Lilian Fernandes; Fiorillo, Edoardo; Fornage, Myriam; Freedman, Barry; Gabrielsen, Maiken E.; Garrett, Melanie E.; Gharib, Sina A.; Gieger, Christian; Gillespie, Nathan; Glahn, David C.; Gordon, Scott D.; Gu, Charles C.; Gu, Dongfeng; Gudbjartsson, Daniel F.; Guo, Xiuqing; Haessler, Jeffrey; Hall, Michael E.; Haller, Toomas; Harris, Kathleen Mullan; He, Jiang; Herd, Pamela; Hewitt, John K.; Hickie, Ian; Hidalgo, Bertha; Hokanson, John E.; Hopfer, Christian; Hottenga, JoukeJan; Hou, Lifang; Huang, Hongyan; Hung, Yi-Jen; Hunter, David J.; Hveem, Kristian; Hwang, Shih-Jen; Hwu, Chii-Min; Iacono, William; Irvin, Marguerite R.; Jee, Yon Ho; Johnson, Eric O.; Joo, Yoonjung Y.; Jorgenson, Eric; Justice, Anne E.; Kamatani, Yoichiro; Kaplan, Robert C.; Kaprio, Jaakko; Kardia, Sharon L. R.; Keller, Matthew C.; Kelly, Tanika N.; Kooperberg, Charles; Korhonen, Tellervo; Kraft, Peter; Krauter, Kenneth; Kuusisto, Johanna; Laakso, Markku; Lasky-Su, Jessica; Lee, Wen-Jane; Lee, James J.; Levy, Daniel; Li, Liming; Li, Kevin; Li, Yuqing; Lin, Kuang; Lind, Penelope A.; Liu, Chunyu; Lloyd-Jones, Donald M.; Lutz, Sharon M.; Ma, Jiantao; Magi, Reedik; Manichaikul, Ani; Martin, Nicholas G.; Mathur, Ravi; Matoba, Nana; McArdle, Patrick F.; McGue, Matt; McQueen, Matthew B.; Medland, Sarah E.; Metspalu, Andres; Meyers, Deborah A.; Millwood, Iona Y.; Mitchell, Braxton D.; Mohlke, Karen L.; Moll, Matthew; Montasser, May E.; Morrison, Alanna C.; Mulas, Antonella; Nielsen, Jonas B.; North, Kari E.; Oelsner, Elizabeth C.; Okada, Yukinori; Orru, Valeria; Palmer, Nicholette D.; Palviainen, Teemu; Pandit, Anita; Park, S. Lani; Peters, Ulrike; Peters, Annette; Peyser, Patricia A.; Polderman, Tinca J. C.; Rafaels, Nicholas; Redline, Susan; Reed, Robert M.; Reiner, Alex P.; Rice, John P.; Rich, Stephen S.; Richmond, Nicole E.; Roan, Carol; Rotter, Jerome; Rueschman, Michael N.; Runarsdottir, Valgerdur; Saccone, Nancy L.; Schwartz, David A.; Shadyab, Aladdin H.; Shi, Jingchunzi; Shringarpure, Suyash S.; Sicinski, Kamil; Skogholt, Anne Heidi; Smith, Jennifer A.; Smith, Nicholas L.; Sotoodehnia, Nona; Stallings, Michael C.; Stefansson, Hreinn; Stefansson, Kari; Stitzel, Jerry A.; Sun, Xiao; Syed, Moin; Tal-Singer, Ruth; Taylor, Amy E.; Taylor, Kent D.; Telen, Marilyn J.; Thai, Khanh K.; Tiwari, Hemant; Turman, Constance; Tyrfingsson, Thorarinn; Wall, Tamara L.; Walters, Robin G.; Weir, David R.; Weiss, Scott T.; White, Wendy B.; Whitfield, John B.; Wiggins, Kerri L.; Willemsen, Gonneke; Willer, Cristen J.; Winsvold, Bendik S.; Xu, Huichun; Yanek, Lisa R.; Yin, Jie; Young, Kristin L.; Young, Kendra A.; Yu, Bing; Zhao, Wei; Zhou, Wei; Zollner, Sebastian; Zuccolo, Luisa; Project, The Biobank Japan; Batini, Chiara; Bergen, Andrew W.; Bierut, Laura J.; David, Sean P.; Taliun, Sarah A. Gagliano; Hancock, Dana B.; Jiang, Bibo; Munafo, Marcus R.; Thorgeirsson, Thorgeir E.; Liu, Dajiang J.; Vrieze, Scott (2022)
    Tobacco and alcohol use are heritable behaviours associated with 15% and 5.3% of worldwide deaths, respectively, due largely to broad increased risk for disease and injury(1-4). These substances are used across the globe, yet genome-wide association studies have focused largely on individuals of European ancestries(5). Here we leveraged global genetic diversity across 3.4 million individuals from four major clines of global ancestry (approximately 21% non-European) to power the discovery and fine-mapping of genomic loci associated with tobacco and alcohol use, to inform function of these loci via ancestry-aware transcriptome-wide association studies, and to evaluate the genetic architecture and predictive power of polygenic risk within and across populations. We found that increases in sample size and genetic diversity improved locus identification and fine-mapping resolution, and that a large majority of the 3,823 associated variants (from 2,143 loci) showed consistent effect sizes across ancestry dimensions. However, polygenic risk scores developed in one ancestry performed poorly in others, highlighting the continued need to increase sample sizes of diverse ancestries to realize any potential benefit of polygenic prediction.
  • Frosen, Juhana; Rezai Jahromi, Behnam; Hernesniemi, Juha (2016)
  • CENTER-TBI Collaborators; Gravesteijn, Benjamin Y.; Nieboer, Daan; Ercole, Ari; Palotie, Aarno; Piippo-Karjalainen, Anna; Pirinen, Matti; Posti, Jussi P.; Raj, Rahul; Ripatti, Samuli; Tenovuo, Olli; Takala, Riikka (2020)
    Objective: We aimed to explore the added value of common machine learning (ML) algorithms for prediction of outcome for moderate and severe traumatic brain injury. Study Design and Setting: We performed logistic regression (LR), lasso regression, and ridge regression with key baseline predictors in the IMPACT-II database (15 studies, n = 11,022). ML algorithms included support vector machines, random forests, gradient boosting machines, and artificial neural networks and were trained using the same predictors. To assess generalizability of predictions, we performed internal, internal-external, and external validation on the recent CENTER-TBI study (patients with Glasgow Coma Scale Results: In the IMPACT-II database, 3,332/11,022 (30%) died and 5,233(48%) had unfavorable outcome (Glasgow Outcome Scale less than 4). In the CENTER-TBI study, 348/1,554(29%) died and 651(54%) had unfavorable outcome. Discrimination and calibration varied widely between the studies and less so between the studied algorithms. The mean area under the curve was 0.82 for mortality and 0.77 for unfavorable outcomes in the CENTER-TBI study. Conclusion: ML algorithms may not outperform traditional regression approaches in a low-dimensional setting for outcome prediction after moderate or severe traumatic brain injury. Similar to regression-based prediction models, ML algorithms should be rigorously validated to ensure applicability to new populations. (C) 2020 The Authors. Published by Elsevier Inc.
  • Rypdal, Veronika; Arnstad, Ellen D; Aalto, Kristiina; Berntson, Lillemor; Ekelund, Maria; Fasth, Anders; Glerup, Mia; Herlin, Troels; Nielsen, Susan; Peltoniemi, Suvi; Zak, Marek; Rygg, Marite; Rypdal, Martin; Nordal, Ellen (BioMed Central, 2018)
    Abstract Background The aim was to develop prediction rules that may guide early treatment decisions based on baseline clinical predictors of long-term unfavorable outcome in juvenile idiopathic arthritis (JIA). Methods In the Nordic JIA cohort, we assessed baseline disease characteristics as predictors of the following outcomes 8 years after disease onset. Non-achievement of remission off medication according to the preliminary Wallace criteria, functional disability assessed by Childhood Health Assessment Questionnaire (CHAQ) and Physical Summary Score (PhS) of the Child Health Questionnaire, and articular damage assessed by the Juvenile Arthritis Damage Index-Articular (JADI-A). Multivariable models were constructed, and cross-validations were performed by repeated partitioning of the cohort into training sets for developing prediction models and validation sets to test predictive ability. Results The total cohort constituted 423 children. Remission status was available in 410 children: 244 (59.5%) of these did not achieve remission off medication at the final study visit. Functional disability was present in 111/340 (32.7%) children assessed by CHAQ and 40/199 (20.1%) by PhS, and joint damage was found in 29/216 (13.4%). Model performance was acceptable for making predictions of long-term outcome. In validation sets, the area under the curves (AUCs) in the receiver operating characteristic (ROC) curves were 0.78 (IQR 0.72–0.82) for non-achievement of remission off medication, 0.73 (IQR 0.67–0.76) for functional disability assessed by CHAQ, 0.74 (IQR 0.65–0.80) for functional disability assessed by PhS, and 0.73 (IQR 0.63–0.76) for joint damage using JADI-A. Conclusion The feasibility of making long-term predictions of JIA outcome based on early clinical assessment is demonstrated. The prediction models have acceptable precision and require only readily available baseline variables. Further testing in other cohorts is warranted.
  • Rypdal, Veronika; Arnstad, Ellen Dalen; Aalto, Kristiina; Berntson, Lillemor; Ekelund, Maria; Fasth, Anders; Glerup, Mia; Herlin, Troels; Nielsen, Susan; Peltoniemi, Suvi; Zak, Marek; Rygg, Marite; Rypdal, Martin; Nordal, Ellen (2018)
    Background: The aim was to develop prediction rules that may guide early treatment decisions based on baseline clinical predictors of long-term unfavorable outcome in juvenile idiopathic arthritis (JIA). Methods: In the Nordic JIA cohort, we assessed baseline disease characteristics as predictors of the following outcomes 8 years after disease onset. Non-achievement of remission off medication according to the preliminary Wallace criteria, functional disability assessed by Childhood Health Assessment Questionnaire (CHAQ) and Physical Summary Score (PhS) of the Child Health Questionnaire, and articular damage assessed by the Juvenile Arthritis Damage Index-Articular (JADI-A). Multivariable models were constructed, and cross-validations were performed by repeated partitioning of the cohort into training sets for developing prediction models and validation sets to test predictive ability. Results: The total cohort constituted 423 children. Remission status was available in 410 children: 244 (59.5%) of these did not achieve remission off medication at the final study visit. Functional disability was present in 111/340 (32.7%) children assessed by CHAQ and 40/199 (20.1%) by PhS, and joint damage was found in 29/216 (13.4%). Model performance was acceptable for making predictions of long-term outcome. In validation sets, the area under the curves (AUCs) in the receiver operating characteristic (ROC) curves were 0.78 (IQR 0.72-0.82) for non-achievement of remission off medication, 0.73 (IQR 0.67-0.76) for functional disability assessed by CHAQ, 0.74 (IQR 0.65-0.80) for functional disability assessed by PhS, and 0.73 (IQR 0.63-0.76) for joint damage using JADI-A. Conclusion: The feasibility of making long-term predictions of JIA outcome based on early clinical assessment is demonstrated. The prediction models have acceptable precision and require only readily available baseline variables. Further testing in other cohorts is warranted.
  • Hall, Anette; Pekkala, Timo; Polvikoski, Tuomo; van Gils, Mark; Kivipelto, Miia; Lötjönen, Jyrki; Mattila, Jussi; Kero, Mia; Myllykangas, Liisa; Mäkelä, Mira; Oinas, Minna; Paetau, Anders; Soininen, Hilkka; Tanskanen, Maarit; Solomon, Alina (2019)
    BackgroundWe developed multifactorial models for predicting incident dementia and brain pathology in the oldest old using the Vantaa 85+ cohort.MethodsWe included participants without dementia at baseline and at least 2 years of follow-up (N=245) for dementia prediction or with autopsy data (N=163) for pathology. A supervised machine learning method was used for model development, considering sociodemographic, cognitive, clinical, vascular, and lifestyle factors, as well as APOE genotype. Neuropathological assessments included -amyloid, neurofibrillary tangles and neuritic plaques, cerebral amyloid angiopathy (CAA), macro- and microscopic infarcts, -synuclein pathology, hippocampal sclerosis, and TDP-43.ResultsPrediction model performance was evaluated using AUC for 10x10-fold cross-validation. Overall AUCs were 0.73 for dementia, 0.64-0.68 for Alzheimer's disease (AD)- or amyloid-related pathologies, 0.72 for macroinfarcts, and 0.61 for microinfarcts. Predictors for dementia were different from those in previous reports of younger populations; for example, age, sex, and vascular and lifestyle factors were not predictive. Predictors for dementia versus pathology were also different, because cognition and education predicted dementia but not AD- or amyloid-related pathologies. APOE genotype was most consistently present across all models. APOE alleles had a different impact: epsilon 4 did not predict dementia, but it did predict all AD- or amyloid-related pathologies; epsilon 2 predicted dementia, but it was protective against amyloid and neuropathological AD; and epsilon 3 epsilon 3 was protective against dementia, neurofibrillary tangles, and CAA. Very few other factors were predictive of pathology.ConclusionsDifferences between predictors for dementia in younger old versus oldest old populations, as well as for dementia versus pathology, should be considered more carefully in future studies.
  • Hall, Anette; Pekkala, Timo; Polvikoski, Tuomo; van Gils, Mark; Kivipelto, Miia; Lötjönen, Jyrki; Mattila, Jussi; Kero, Mia; Myllykangas, Liisa; Mäkelä, Mira; Oinas, Minna; Paetau, Anders; Soininen, Hilkka; Tanskanen, Maarit; Solomon, Alina (BioMed Central, 2019)
    Abstract Background We developed multifactorial models for predicting incident dementia and brain pathology in the oldest old using the Vantaa 85+ cohort. Methods We included participants without dementia at baseline and at least 2 years of follow-up (N = 245) for dementia prediction or with autopsy data (N = 163) for pathology. A supervised machine learning method was used for model development, considering sociodemographic, cognitive, clinical, vascular, and lifestyle factors, as well as APOE genotype. Neuropathological assessments included β-amyloid, neurofibrillary tangles and neuritic plaques, cerebral amyloid angiopathy (CAA), macro- and microscopic infarcts, α-synuclein pathology, hippocampal sclerosis, and TDP-43. Results Prediction model performance was evaluated using AUC for 10 × 10-fold cross-validation. Overall AUCs were 0.73 for dementia, 0.64–0.68 for Alzheimer’s disease (AD)- or amyloid-related pathologies, 0.72 for macroinfarcts, and 0.61 for microinfarcts. Predictors for dementia were different from those in previous reports of younger populations; for example, age, sex, and vascular and lifestyle factors were not predictive. Predictors for dementia versus pathology were also different, because cognition and education predicted dementia but not AD- or amyloid-related pathologies. APOE genotype was most consistently present across all models. APOE alleles had a different impact: ε4 did not predict dementia, but it did predict all AD- or amyloid-related pathologies; ε2 predicted dementia, but it was protective against amyloid and neuropathological AD; and ε3ε3 was protective against dementia, neurofibrillary tangles, and CAA. Very few other factors were predictive of pathology. Conclusions Differences between predictors for dementia in younger old versus oldest old populations, as well as for dementia versus pathology, should be considered more carefully in future studies.
  • Keikkala, Elina; Forsten, Janina; Ritvos, Olli; Stenman, Ulf-Håkan; Kajantie, Eero; Hämäläinen, Esa; Räikkönen, Katri; Villa, Pia M.; Laivuori, Hannele (2021)
    Objectives: Maternal serum inhibin-A , pregnancy associated plasma protein-A (PAPP-A) and PAPP-A2 together with placental growth factor (PlGF), maternal risk factors and uterine arter y pulsatility inde x (UtA PI) were analysed to study thei r ability to predict pre-eclampsia (PE). Study design: Serial serum samples for the nested case-control study were collected prospectively at 12-14, 18-20 and 26-28 weeks of gestation from 11 women who later developed early-onset PE (EO PE , diagnosis < 34 + 0 weeks of gestation), 34 women who developed late-onset PE (LO PE , diagnosis 2 34 + 0 weeks) and 89 controls. Main outcome measures: Gestational age-adjusted multiples of the median (MoM) values were calculated for biomarker concentrations. Multivariate regression analyses were performed to combine first trimester bio-markers, previously reported results on PlGF, maternal risk factors and UtA PI. Area under cu r v e (AUC) values and 95% confidence intervals (CIs) for the prediction of PE and its subtypes were calculated . Results: A high first trimester inhibin-A predicted PE (AUC 0.618, 95%CI, 0.513-0.724), whereas PAPP-A and PlGF predicted only EO PE (0.701, 0.562-0.840 and 0.798, 0.686-0.909, respectively). At 26-28 weeks PAPP-A2 and inhibin-A predicted a l l PE subtypes. In the multivariate setting inhibin-A combined with maternal pre-pregnancy body mass index, prior PE and mean UtA PI predicted PE (0.811,0.726-0.896) and LO PE (0.824, 0.733-0.914). Conclusions: At first trimester inhibin-A show potential ability to predict not only EO PE but also LO PE whereas PlGF and PAPP-A predict only EO PE. At late second trimester inhibin-A and PAPP-A2 might be usef u l for short-term prediction of PE.
  • Piirainen, Sirke; Lehikoinen, Aleksi; Husby, Magne; Kålås, John Atle; Lindström, Åke; Ovaskainen, Otso (2023)
    Aim: Species distribution models (SDMs) are widely used to make predictions on how species distributions may change as a response to climatic change. To assess the reliability of those predictions, they need to be critically validated with respect to what they are used for. While ecologists are typically interested in how and where distributions will change, we argue that SDMs have seldom been evaluated in terms of their capacity to predict such change. Instead, typical retrospective validation methods estimate model's ability to predict to only one static time in future. Here, we apply two validation methods, one that predicts and evaluates a static pattern, while the other measures change and compare their estimates of predictive performance. Location: Fennoscandia.Methods: We applied a joint SDM to model the distributions of 120 bird species in four model validation settings. We trained models with a dataset from 1975 to 1999 and predicted species' future occurrence and abundance in two ways: for one static time period (2013- 2016, "static validation') and for a change between two time periods (difference between 1996- 1999 and 2013- 2016, "change validation'). We then measured predictive performance using correlation between predicted and observed values. We also related predictive performance to species traits. Results: Even though static validation method evaluated predictive performance as good, change method indicated very poor performance. Predictive performance was not strongly related to any trait.Main Conclusions: Static validation method might overestimate predictive performance by not revealing the model's inability to predict change events. If species' distributions remain mostly stable, then even an unfit model can predict the near future well due to temporal autocorrelation. We urge caution when working with forecasts of changes in spatial patterns of species occupancy or abundance, even for SDMs that are based on time series datasets unless they are critically validated for forecasting such change.
  • FullPIERS Grp; Ukah, U. Vivian; Payne, Beth; Karjalainen, Hanna; Kortelainen, Eija; Seed, Paul T.; Conti-Ramsden, Frances Inez; Cao, Vivien; Laivuori, Hannele; Hutcheon, Jennifer; Chappell, Lucy; Ansermino, J. Mark; Vatish, Manu; Redman, Christopher; Lee, Tang; Li, Larry; Magee, Laura A.; von Dadelszen, Peter (2019)
    The fullPIERS model is a risk prediction model developed to predict adverse maternal outcomes within 48 h for women admitted with pre-eclampsia. External validation of the model is required before implementation for clinical use. We assessed the temporal and external validity of the fullPIERS model in high income settings using five cohorts collected between 2003 and 2016, from tertiary hospitals in Canada, the United States of America, Finland and the United Kingdom. The cohorts were grouped into three datasets for assessing the primary external, and temporal validity, and broader transportability of the model. The predicted risks of developing an adverse maternal outcome were calculated using the model equation and model performance was evaluated based on discrimination, calibration, and stratification. Our study included a total of 2429 women, with an adverse maternal outcome rate of 6.7%, 6.6%, and 7.0% in the primary external, temporal, and combined (broader) validation cohorts, respectively. The model had good discrimination in all datasets: 0.81 (95%CI 0.75-0.86), 0.82 (95%CI 0.76-0.87), and 0.75 (95%CI 0.71-0.80) for the primary external, temporal, and broader validation datasets, respectively. Calibration was best for the temporal cohort but poor in the broader validation dataset The likelihood ratios estimated to rule in adverse maternal outcomes were high at a cut-off of >= 30% in all datasets. The fullPIERS model is temporally and externally valid and will be useful in the management of women with pre-eclampsia in high income settings although model recalibration is required to improve performance, specifically in the broader healthcare settings.
  • Auvinen, Anna-Maaria; Luiro, Kaisu; Jokelainen, Jari; Järvelä, Ilkka; Knip, Mikael; Auvinen, Juha; Tapanainen, Juha S. (2020)
    Aims/hypothesis The aim of this work was to examine the progression to type 1 and type 2 diabetes after gestational diabetes mellitus (GDM) in a 23 year follow-up study. Methods We carried out a cohort study of 391 women with GDM diagnosed by an OGTT or the use of insulin treatment during pregnancy, and 391 age- and parity-matched control participants, who delivered in 1984-1994 at the Oulu University Hospital, Finland. Diagnostic cut-off levels for glucose were as follows: fasting, >= 4.8 mmol/l; 1 h, >= 10.0 mmol/l; and 2 h, >= 8.7 mmol/l. Two follow-up questionnaires were sent (in 1995-1996 and 2012-2013) to assess the progression to type 1 and type 2 diabetes. Mean follow-up time was 23.1 (range 18.7-28.8) years. Results Type 1 diabetes developed (5.7%) during the first 7 years after GDM pregnancy and was predictable at a 2 h OGTT value of 11.9 mmol/l during pregnancy (receiver operating characteristic analysis: AUC 0.91, sensitivity 76.5%, specificity 96.0%). Type 2 diabetes increased linearly to 50.4% by the end of the follow-up period and was moderately predictable with fasting glucose (AUC 0.69, sensitivity 63.5%, specificity 68.2%) at a level of 5.1 mmol/l (identical to the fasting glucose cut-off recommended by the International Association of Diabetes and Pregnancy Study Groups [IADPSG) and WHO]). Conclusions/interpretation All women with GDM should be intensively monitored for a decade, after which the risk for type 1 diabetes is minimal. However, the incidence of type 2 diabetes remains linear, and therefore individualised lifelong follow-up is recommended.
  • ReACCh-Out NoSPeR Investigators; Rypdal, Veronika (2019)
    Background: Models to predict disease course and long-term outcome based on clinical characteristics at disease onset may guide early treatment strategies in juvenile idiopathic arthritis (JIA). Before a prediction model can be recommended for use in clinical practice, it needs to be validated in a different cohort than the one used for building the model. The aim of the current study was to validate the predictive performance of the Canadian prediction model developed by Guzman et al. and the Nordic model derived from Rypdal et al. to predict severe disease course and non-achievement of remission in Nordic patients with JIA. Methods: The Canadian and Nordic multivariable logistic regression models were evaluated in the Nordic JIA cohort for prediction of non-achievement of remission, and the data-driven outcome denoted severe disease course. A total of 440 patients in the Nordic cohort with a baseline visit and an 8-year visit were included. The Canadian prediction model was first externally validated exactly as published. Both the Nordic and Canadian models were subsequently evaluated with repeated fine-tuning of model coefficients in training sets and testing in disjoint validation sets. The predictive performances of the models were assessed with receiver operating characteristic curves and C-indices. A model with a C-index above 0.7 was considered useful for clinical prediction. Results: The Canadian prediction model had excellent predictive ability and was comparable in performance to the Nordic model in predicting severe disease course in the Nordic JIA cohort. The Canadian model yielded a C-index of 0.85 (IQR 0.83-0.87) for prediction of severe disease course and a C-index of 0.66 (0.63-0.68) for prediction of non-achievement of remission when applied directly. The median C-indices after fine-tuning were 0.85 (0.80-0.89) and 0.69 (0.65-0.73), respectively. Internal validation of the Nordic model for prediction of severe disease course resulted in a median C-index of 0.90 (0.86-0.92). Conclusions: External validation of the Canadian model and internal validation of the Nordic model with severe disease course as outcome confirm their predictive abilities. Our findings suggest that predicting long-term remission is more challenging than predicting severe disease course.