Overview
Dr Zirk-Sadowski’s work focuses on observational studies of pharmaceutical treatment in later life. Studies are run in collaboration with Dr Alessandro Ble, Professor William Henley and Professor David Melzer at the Melzer research group (Epidemiology and Public Health). Dr Zirk-Sadowski is a Fellow of the Royal Statistical Society, and a life member of Darwin College, University of Cambridge.
Prior to joining the University of Exeter Medical School Dr Zirk-Sadowski was a SSRMC Lecturer in statistics on the interdepartmental Social Sciences Research Methods Programme at the University of Cambridge (2010-2015). He has also held a postdoctoral position in the statistical epidemiology of middle-ear disease at the Eurotitis-2 Study Group/MRC Multicentre Otitis Media Study Group, University of Cambridge, and has worked as a Consultant Statistician for prospective cohort projects of the Criminological Research Unit, Swiss Federal Institute of Technology ETH in Zurich and the Institute of Criminology, University of Cambridge.
His PhD was done at the Centre for Neuroscience in Education (CNE) at the University of Cambridge. One of his methodological interests has been in strengthening inference from observational data with latent factor techniques. His observational and experimental investigations studied human cognitive performance with behavioural, psychophysiological and fMRI approaches in collaboration with the Health Neuroscience Group, Department of Psychiatry at the University of Cambridge. His PhD research included a large-scale observational and experimental project on human risk-taking and numerical competence designed by Dr Mike Aitken and Prof Sir David Spiegelhalter at BBC Lab UK. Prior to joining the CNE Dr Zirk-Sadowski undertook five years of full-time training in psychology at the Warsaw School of Social Psychology, which is affiliated with the Nencki Institute of Experimental Biology. Dr Zirk-Sadowski received PhD research support from the Sir Richard Stapley Educational Trust, the Sidney Perry Foundation, other British grant awarding bodies, and the Jolanta and Leszek Czarnecki Foundation.
Qualifications
- 2014 PhD Experimental Psychology, University of Cambridge.
- 2009 MSc Psychology (five years of full time training), Warsaw School of Social Psychology
Research
Research interests
- Research design
- Methods for strengthening causal inference from observational data
- Mediation analysis and associated power issues
Current scientific interests are related to proton pump inhibitors and health outcomes in later life.
Broad Research Specialisms
Dr Zirk-Sadowski has joined the Epidemiology and Public Health to study observational associations of proton-pump inhibitors within the Clinical Practice Research Datalink (CPRD).
Dr Zirk-Sadowski as a statistical life scientist has specialized in applying multivariate frequentist and Bayesian methods to complex cross-sectional and longitudinal data. His prior scientific work done at Cambridge explored cognition and indicators of human learning numbers in the context of mental health symptomatology. In his collaboration with Dr Mike Aitken and Professor Sir David Spiegelhalter, Dr Zirk-Sadowski explored a large scale data from over 83,000 people collected by the BBC Lab UK. His statistical consulting for the Swiss Federal Institute of Technology ETH in Zurich and the Institute of Criminology in Cambridge focused on applying latent class multivariate techniques to criminological and mental health data. Dr Zirk-Sadowski's contribution to the epidemiology of middle ear disease at the Eurotitis-2 Study Group at Cambridge has helped built access to structural equation investigations of complex RCT relations embedded within observational data of otitis media symptoms in a large European database.
Publications
Key publications | Publications by category | Publications by year
Publications by category
Journal articles
Zirk-Sadowski J, Masoli J, Strain WD, Delgado J, Henley W, Hamilton W, Melzer D, Ble A (In Press). Proton-Pump Inhibitors and Fragility Fractures in Vulnerable Older Patients.
The American Journal of Gastroenterology (Elsevier) Full text.
Ble A, Hughes PM, Delgado J, Masoli JA, Bowman K, Zirk-Sadowski J, Mujica Mota RE, Henley WE, Melzer D (2017). Safety and Effectiveness of Statins for Prevention of Recurrent Myocardial Infarction in 12 156 Typical Older Patients: a Quasi-Experimental Study.
J Gerontol a Biol Sci Med Sci,
72(2), 243-250.
Abstract:
Safety and Effectiveness of Statins for Prevention of Recurrent Myocardial Infarction in 12 156 Typical Older Patients: a Quasi-Experimental Study.
BACKGROUND: There is limited evidence on statin risk and effectiveness for patients aged 80+. We estimated risk of recurrent myocardial infarction, muscle-related and other adverse events, and statin-related incremental costs in "real-world" older patients treated with statins versus no statins. METHODS: We used primary care electronic medical records from the UK Clinical Practice Research Datalink. Subhazard ratios (competing risk of death) for myocardial infarction recurrence (primary end point), falls, fractures, ischemic stroke, and dementia, and hazard ratios (Cox) for all-cause mortality were used to compare older (60+) statin users and 1:1 propensity-score-matched controls (n = 12,156). Participants were followed-up for 10 years. RESULTS: Mean age was 76.5±9.2 years; 45.5% were women. Statins were associated with near significant reduction in myocardial infarction recurrence (subhazard ratio = 0.84, 0.69-1.02, p =. 073), with protective effect in the 60-79 age group (0.73, 0.57-0.94) but a nonsignificant result in the 80+ group (1.06, 0.78-1.44; age interaction p =. 094). No significant associations were found for stroke or dementia. Data suggest an increased risk of falls (1.36, 1.17-1.60) and fractures (1.33, 1.04-1.69) in the first 2 years of treatment, particularly in the 80+ group. Treatment was associated with lower all-cause mortality. Statin use was associated with health care cost savings in the 60-79 group but higher costs in the 80+ group. CONCLUSIONS: Estimates of statin effectiveness for the prevention of recurrent myocardial infarction in patients aged 60-79 years were similar to trial results, but more evidence is needed in the older group. There may be an excess of falls and fractures in very old patients, which deserves further investigation.
Abstract.
Author URL.
Full text.
Murray AL, Obsuth I, Zirk-Sadowski J, Ribeaud D, Eisner M (2016). Developmental Relations Between ADHD Symptoms and Reactive Versus Proactive Aggression Across Childhood and Adolescence.
J Atten DisordAbstract:
Developmental Relations Between ADHD Symptoms and Reactive Versus Proactive Aggression Across Childhood and Adolescence.
OBJECTIVE: Past research has provided some preliminary evidence that ADHD and reactive aggression have overlapping neurocognitive bases. Based on this, we tested the hypothesis that ADHD symptoms are closely coupled in developmental terms with reactive aggression, more so than with proactive aggression with which it has been postulated to be only indirectly linked. METHOD: We used latent growth curve analysis to estimate the developmental relations between ADHD symptoms and subtypes of aggressive behavior in a normative sample of 1,571 youth (761 female, 810 male) measured from ages 7 to 15. RESULTS: Individual ADHD trajectories were significantly and substantially correlated with individual trajectories in both aggressive subtypes; however, consistent with our hypothesis, the relation with reactive aggression was significantly stronger. CONCLUSION: Our study provides some of the first evidence for a differential relation between ADHD symptoms and aggression subtypes not only cross-sectionally but also in terms of their longitudinal developmental trajectories.
Abstract.
Author URL.
Zirk-Sadowski J, Lamptey C, Devine A, Haggard M, Szűcs D (2014). Young-age gender differences in mathematics mediated by independent control or uncontrollability.
Dev Sci,
17(3), 366-375.
Abstract:
Young-age gender differences in mathematics mediated by independent control or uncontrollability.
We studied whether the origins of math anxiety can be related to a biologically supported framework of stress induction: (un)controllability perception, here indicated by self-reported independent efforts in mathematics. Math anxiety was tested in 182 children (8- to 11-year-olds). Latent factor modeling was used to test hypotheses on plausible causal processes and mediations within competing models in quasi-experimental contrasts. Uncontrollability perception in mathematics, or (in)dependence of efforts, best fit the data as an antecedent of math anxiety. In addition, the relationship of math anxiety with gender was fully mediated by adaptive perception of control (i.e. controllability). That is, young boys differ from girls in terms of their experience of control in mathematics learning. These differences influence math anxiety. Our findings are consistent with recent suggestions in clinical literature according to which uncontrollability makes women more susceptible to fear and anxiety disorders.
Abstract.
Author URL.
Zirk-Sadowski J, Szucs D, Holmes J (2013). Content-specificity in verbal recall: a randomized controlled study.
PLoS One,
8(11).
Abstract:
Content-specificity in verbal recall: a randomized controlled study.
In this controlled experiment we examined whether there are content effects in verbal short-term memory and working memory for verbal stimuli. Thirty-seven participants completed forward and backward digit and letter recall tasks, which were constructed to control for distance effects between stimuli. A maximum-likelihood mixed-effects logistic regression revealed main effects of direction of recall (forward vs backward) and content (digits vs letters). There was an interaction between type of recall and content, in which the recall of digits was superior to the recall of letters in verbal short-term memory but not in verbal working memory. These results demonstrate that the recall of information from verbal short-term memory is content-specific, whilst the recall of information from verbal working memory is content-general.
Abstract.
Author URL.
Full text.
Publications by year
In Press
Zirk-Sadowski J, Masoli J, Strain WD, Delgado J, Henley W, Hamilton W, Melzer D, Ble A (In Press). Proton-Pump Inhibitors and Fragility Fractures in Vulnerable Older Patients.
The American Journal of Gastroenterology (Elsevier) Full text.
2017
Ble A, Hughes PM, Delgado J, Masoli JA, Bowman K, Zirk-Sadowski J, Mujica Mota RE, Henley WE, Melzer D (2017). Safety and Effectiveness of Statins for Prevention of Recurrent Myocardial Infarction in 12 156 Typical Older Patients: a Quasi-Experimental Study.
J Gerontol a Biol Sci Med Sci,
72(2), 243-250.
Abstract:
Safety and Effectiveness of Statins for Prevention of Recurrent Myocardial Infarction in 12 156 Typical Older Patients: a Quasi-Experimental Study.
BACKGROUND: There is limited evidence on statin risk and effectiveness for patients aged 80+. We estimated risk of recurrent myocardial infarction, muscle-related and other adverse events, and statin-related incremental costs in "real-world" older patients treated with statins versus no statins. METHODS: We used primary care electronic medical records from the UK Clinical Practice Research Datalink. Subhazard ratios (competing risk of death) for myocardial infarction recurrence (primary end point), falls, fractures, ischemic stroke, and dementia, and hazard ratios (Cox) for all-cause mortality were used to compare older (60+) statin users and 1:1 propensity-score-matched controls (n = 12,156). Participants were followed-up for 10 years. RESULTS: Mean age was 76.5±9.2 years; 45.5% were women. Statins were associated with near significant reduction in myocardial infarction recurrence (subhazard ratio = 0.84, 0.69-1.02, p =. 073), with protective effect in the 60-79 age group (0.73, 0.57-0.94) but a nonsignificant result in the 80+ group (1.06, 0.78-1.44; age interaction p =. 094). No significant associations were found for stroke or dementia. Data suggest an increased risk of falls (1.36, 1.17-1.60) and fractures (1.33, 1.04-1.69) in the first 2 years of treatment, particularly in the 80+ group. Treatment was associated with lower all-cause mortality. Statin use was associated with health care cost savings in the 60-79 group but higher costs in the 80+ group. CONCLUSIONS: Estimates of statin effectiveness for the prevention of recurrent myocardial infarction in patients aged 60-79 years were similar to trial results, but more evidence is needed in the older group. There may be an excess of falls and fractures in very old patients, which deserves further investigation.
Abstract.
Author URL.
Full text.
2016
Murray AL, Obsuth I, Zirk-Sadowski J, Ribeaud D, Eisner M (2016). Developmental Relations Between ADHD Symptoms and Reactive Versus Proactive Aggression Across Childhood and Adolescence.
J Atten DisordAbstract:
Developmental Relations Between ADHD Symptoms and Reactive Versus Proactive Aggression Across Childhood and Adolescence.
OBJECTIVE: Past research has provided some preliminary evidence that ADHD and reactive aggression have overlapping neurocognitive bases. Based on this, we tested the hypothesis that ADHD symptoms are closely coupled in developmental terms with reactive aggression, more so than with proactive aggression with which it has been postulated to be only indirectly linked. METHOD: We used latent growth curve analysis to estimate the developmental relations between ADHD symptoms and subtypes of aggressive behavior in a normative sample of 1,571 youth (761 female, 810 male) measured from ages 7 to 15. RESULTS: Individual ADHD trajectories were significantly and substantially correlated with individual trajectories in both aggressive subtypes; however, consistent with our hypothesis, the relation with reactive aggression was significantly stronger. CONCLUSION: Our study provides some of the first evidence for a differential relation between ADHD symptoms and aggression subtypes not only cross-sectionally but also in terms of their longitudinal developmental trajectories.
Abstract.
Author URL.
2014
Zirk-Sadowski J, Lamptey C, Devine A, Haggard M, Szűcs D (2014). Young-age gender differences in mathematics mediated by independent control or uncontrollability.
Dev Sci,
17(3), 366-375.
Abstract:
Young-age gender differences in mathematics mediated by independent control or uncontrollability.
We studied whether the origins of math anxiety can be related to a biologically supported framework of stress induction: (un)controllability perception, here indicated by self-reported independent efforts in mathematics. Math anxiety was tested in 182 children (8- to 11-year-olds). Latent factor modeling was used to test hypotheses on plausible causal processes and mediations within competing models in quasi-experimental contrasts. Uncontrollability perception in mathematics, or (in)dependence of efforts, best fit the data as an antecedent of math anxiety. In addition, the relationship of math anxiety with gender was fully mediated by adaptive perception of control (i.e. controllability). That is, young boys differ from girls in terms of their experience of control in mathematics learning. These differences influence math anxiety. Our findings are consistent with recent suggestions in clinical literature according to which uncontrollability makes women more susceptible to fear and anxiety disorders.
Abstract.
Author URL.
2013
Zirk-Sadowski J, Szucs D, Holmes J (2013). Content-specificity in verbal recall: a randomized controlled study.
PLoS One,
8(11).
Abstract:
Content-specificity in verbal recall: a randomized controlled study.
In this controlled experiment we examined whether there are content effects in verbal short-term memory and working memory for verbal stimuli. Thirty-seven participants completed forward and backward digit and letter recall tasks, which were constructed to control for distance effects between stimuli. A maximum-likelihood mixed-effects logistic regression revealed main effects of direction of recall (forward vs backward) and content (digits vs letters). There was an interaction between type of recall and content, in which the recall of digits was superior to the recall of letters in verbal short-term memory but not in verbal working memory. These results demonstrate that the recall of information from verbal short-term memory is content-specific, whilst the recall of information from verbal working memory is content-general.
Abstract.
Author URL.
Full text.
Refresh publications
