Programming challenges of sampling controls to cases from the dynamic risk sets in nested case–control studies

Kiri, Victor A.

doi:10.1179/1757092112z.0000000004

Cited by 4 publications

(3 citation statements)

References 12 publications

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“…This nonexposed group consisted of 4 participants per stroke case, randomly matched to this case on age (within 1 year), sex, and visiting the same examination round, using an incidence density sampling approach. 30 This nonexposed group was free of stroke until the stroke date of their matched case (index date) and their at-risk time for mortality started at the index date. Note that participants could be included as nonexposed several times and could become exposed later on.…”

Section: Discussionmentioning

confidence: 99%

Role of Prestroke Vascular Pathology in Long-Term Prognosis After Stroke

Portegies

Bos

Hofman

et al. 2016

Stroke

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Background and Purpose-Mortality after stroke remains high for years, mostly because of cardiovascular causes. Given that cardiovascular pathology plays an important role in causing the initial stroke, such prestroke pathology might also influence the prognosis after stroke. Within the population-based Rotterdam Study, we examined the proportion of deaths after stroke that are attributable to pre-existent cardiovascular risk factors before stroke (the population attributable risk). Methods-We examined 1237 patients with first-ever stroke and 4928 stroke-free participants (between 1990 and 2012), matched on age, sex, examination round, and stroke date (index date). Cardiovascular risk factors measured on ≈4 years before index date were used as determinants. Participants were continuously followed up for mortality (≈6 years) after the index date. We calculated separate and combined population attributable risk of hypertension, total cholesterol, high-density lipoprotein-cholesterol, body mass index, diabetes mellitus, smoking, transient ischemic attack, and atrial fibrillation. Results-Nine hundred and nineteen patients with stroke and 2654 stroke-free participants died. The combined population attributable risk in patients with stroke was 27% (95% confidence interval, 14%-45%) and in stroke-free participants was 19% (95% confidence interval, 12%-29%). Population attributable risks of diabetes mellitus, smoking, and atrial fibrillation were higher in patients with stroke than in the reference group because of a higher prevalence of risk factors. In addition, people with atrial fibrillation and stroke had a higher hazard ratio for death than those with only atrial fibrillation. Conclusions-One quarter of deaths after stroke could theoretically be prevented with rigorous cardiovascular prevention and treatment, but this should preferably start before stroke occurrence. In addition, research into factors explaining the remaining deaths needs to be encouraged.

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Section: Discussionmentioning

confidence: 99%

Role of Prestroke Vascular Pathology in Long-Term Prognosis After Stroke

Portegies

Bos

Hofman

et al. 2016

Stroke

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“…Then, we selected per stroke patient, 4 participants without stroke, randomly matched to this patient on age (± 1 year), sex, and visiting the same examination round, using an incidence density sampling approach. 2 Participants without stroke were free of stroke at the stroke date of their matched stroke patient (index date) and their time at risk of stroke and dementia was from this index date onwards. Persons could be included as a non-exposed match for multiple stroke patients, and could become exposed themselves later on.…”

Section: Methodsmentioning

confidence: 99%

Prestroke Vascular Pathology and the Risk of Recurrent Stroke and Poststroke Dementia

Portegies¹,

Wolters²,

Hofman³

et al. 2016

Stroke

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Survival after stroke has improved over the past decades, thanks to thrombolytic therapy, specialized stroke units, and better secondary prevention.1,2 However, such improved survival may lead to more people having long-term hazards of stroke, such as recurrent stroke and dementia.3,4 These longterm risks after stroke are not well documented, nor are the factors that determine this risk. In this regard, risk factors that lead to the initial stroke may also predispose to clinical adverse events after stroke. Indeed, we previously showed that 27% of all deaths after stroke can be attributed to risk factors already present before stroke. 5 We now expand on that previous report by investigating recurrent stroke and poststroke dementia and how these are affected by prestroke risk factors. MethodsExtensive details on the Methods are presented in the online-only Data Supplement and are largely identical to a previous article.5 Briefly, this study was embedded within the population-based Rotterdam Study, 6 which totals 14,926 participants aged >45 years, who were repeatedly examined every 4 years. We selected 1243 participants who had an incident stroke between 1990 and 2012 and matched these to 4 participants without stroke with matching done on date of selection, age, sex, and visit to the same examination round, using an incidence density sampling. Participants were then followed up for the occurrence of stroke or dementia until January 1, 2012. In total, 1237 participants with stroke and 4928 stroke-free participants were eligible for the analyses with recurrent stroke and, respectively, 993 and 4363 for the dementia analyses ( Figure I and Table I in the online-only Data Supplement). ResultsRisk of recurrent stroke and dementia was highest in the shortterm, but even beyond the first year, the risk of recurrent stroke (incidence rate ratio, 3.16 [95% confidence interval, 2.59-3.85]) and dementia (incidence rate ratio, 1.73 [1.38-2.17]) remained increased. However, these differences were only statistically significant from years 1 to 5 (Figure).Participants with stroke had a worse cardiovascular profile than participants without stroke (Table I online-only Data Supplement). Main factors contributing to a recurrent Background and Purpose-Improved short-term survival after stroke has necessitated quantifying risk and risk factors of long-term sequelae after stroke (ie, recurrent stroke and dementia). This risk may be influenced by exposure to cardiovascular risk factors before the initial stroke. Within the population-based Rotterdam Study, we determined the long-term risk of recurrent stroke and dementia, and the proportion of recurrent strokes and poststroke dementia cases that are attributable to prestroke cardiovascular risk factors (ie, the population attributable risk). Methods-We followed up 1237 patients with first-ever stroke and 4928 stroke-free participants, matched on age, sex, examination round, and stroke date (index date), for the occurrence of stroke or dementia. We calculated incidence rates in...

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“…However, it should be noted that path sampling (by design) is based on more unique controls selected [ 11 ] implying that it naturally uses a larger sample of unique patients to achieve those similar standard errors as compared to incidence density sampling. This knowledge gained is directly useful in improving nested case-control studies that have recently gained an interest in safety studies[ 26 , 27 ]. This study provides insights regarding choice of nested case-control design and the burden of AEs on treatment non-adherence and study non-completion in IPTp trials.…”

Section: Discussionmentioning

confidence: 99%

Effect of adverse events on non-adherence and study non-completion in malaria chemoprevention during pregnancy trial: A nested case control study

et al. 2022

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Background In drug trials, adverse events (AEs) burden can induce treatment non-adherence or discontinuation. The non-adherence and discontinuation induce selection bias, affecting drug safety interpretation. Nested case-control (NCC) study can efficiently quantify the impact of the AEs, although choice of sampling approach is challenging. We investigated whether NCC study with incidence density sampling is more efficient than NCC with path sampling under conditional logistic or weighted Cox models in assessing the effect of AEs on treatment non-adherence and participation in preventive antimalarial drug during pregnancy trial. Methods Using data from a trial of medication to prevent malaria in pregnancy that randomized 600 women to receive chloroquine or sulfadoxine-pyrimethamine during pregnancy, we conducted a NCC study assessing the role of prospectively collected AEs, as exposure of interest, on treatment non-adherence and study non-completion. We compared estimates from NCC study with incidence density against those from NCC with path sampling under conditional logistic and weighted Cox models. Results Out of 599 women with the outcomes of interest, 474 (79%) experienced at least one AE before delivery. For conditional logistic model, the hazard ratio for the effect of AE occurrence on treatment non-adherence was 0.70 (95% CI: 0.42, 1.17; p = 0.175) under incidence density sampling and 0.68 (95% CI: 0.41, 1.13; p = 0.137) for path sampling. For study non-completion, the hazard ratio was 1.02 (95% CI: 0.56, 1.83; p = 0.955) under incidence density sampling and 0.85 (95% CI: 0.45, 1.60; p = 0.619) under path sampling. We obtained similar hazard ratios and standard errors under incidence density sampling and path sampling whether weighted Cox or conditional logistic models were used. Conclusion NCC with incidence density sampling and NCC with path sampling are practically similar in efficiency whether conditional logistic or weighted Cox analytical methods although path sampling uses more unique controls to achieve the similar estimates. Trial registration ClinicalTrials.gov: NCT01443130.

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Programming challenges of sampling controls to cases from the dynamic risk sets in nested case–control studies

Cited by 4 publications

References 12 publications

Role of Prestroke Vascular Pathology in Long-Term Prognosis After Stroke

Role of Prestroke Vascular Pathology in Long-Term Prognosis After Stroke

Prestroke Vascular Pathology and the Risk of Recurrent Stroke and Poststroke Dementia

Effect of adverse events on non-adherence and study non-completion in malaria chemoprevention during pregnancy trial: A nested case control study

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