Study retention and attrition in a longitudinal cohort study including patient-reported outcomes, fieldwork and biobank samples: results of the Netherlands quality of life and Biomedical cohort study (NET-QUBIC) among 739 head and neck cancer patients and 262 informal caregivers

Abstract

Background Longitudinal observational cohort studies in cancer patients are important to move research and clinical practice forward. Continued study participation (study retention) is of importance to maintain the statistical power of research and facilitate representativeness of study findings. This study aimed to investigate study retention and attrition (drop-out) and its associated sociodemographic and clinical factors among head and neck cancer (HNC) patients and informal caregivers included in the Netherlands Quality of Life and Biomedical Cohort Study (NET-QUBIC). Methods NET-QUBIC is a longitudinal cohort study among 739 HNC patients and 262 informal caregivers with collection of patient-reported outcome measures (PROMs), fieldwork data (interview, objective tests and medical examination) and biobank materials. Study retention and attrition was described from baseline (before treatment) up to 2-years follow-up (after treatment). Sociodemographic and clinical characteristics associated with retention in NET-QUBIC components at baseline (PROMs, fieldwork and biobank samples) and retention in general (participation in at least one component) were investigated using Chi-square, Fisher exact or independent t-tests (p< 0.05). Results Study retention at 2-years follow-up was 80% among patients alive (66% among all patients) and 70% among caregivers of patients who were alive and participating (52% among all caregivers). Attrition was most often caused by mortality, and logistic, physical, or psychological-related reasons. Tumor stage I/II, better physical performance and better (lower) comorbidity score were associated with participation in the PROMs component among patients. No factors associated with participation in the fieldwork component (patients), overall sample collection (patients and caregivers) or PROMs component (caregivers) were identified. A better performance and comorbidity score (among patients) and higher age (among caregivers) were associated with study retention at 2-years follow-up. Conclusions Retention rates were high at two years follow-up (i.e. 80% among HNC patients alive and 70% among informal caregivers with an active patient). Nevertheless, some selection was shown in terms of tumor stage, physical performance, comorbidity and age, which might limit representativeness of NET-QUBIC data and samples. To facilitate representativeness of study findings future cohort studies might benefit from oversampling specific subgroups, such as patients with poor clinical outcomes or higher comorbidity and younger caregivers.

The course of swallowing problems in the first 2 years after diagnosis of head and neck cancer

“…Data were used of 739 patients with HNC participating in the prospective NETherlands Quality of Life and Biomedical Cohort study in HNC cancer (NET-QUBIC), of which details were published previously [32,33]. Recruitment took place in 7 HNC centers throughout the Netherlands between 2014 and 2018.…”

“…All patients signed written informed consent before participation. The study protocol of this prospective observational cohort study was approved by the Medical Ethics Committee of the VUmc (NL45051.029.13) and all local participating centers [32,33]. In the present study, patients were included when they had completed the SWAL-QOL questionnaire at any given time point.…”

“…In addition, patients with a larynx and hypopharynx tumor were combined as well (n = 205 and n = 52 in the total NET-QUBC population, respectively). A limitation of this study was the fact that only 374 patients filled in the questionnaire 2 years after treatment [32,33]. The 739 patients that were included in the NET-QUBIC research are already a selection of the total HNC population, in which it is unknown whether the non-responders perform worse or better regarding swallowing problems.…”

Psychological Problems among Head and Neck Cancer Patients in Relation to Utilization of Healthcare and Informal Care and Costs in the First Two Years after Diagnosis

“…Reasons for drop-out are shown in Figure 1. More detailed information on the study flow is provided in a previous published study [30].…”

Interventions for head and neck cancer survivors: Systematic review

“…51 Another proposed solution to loss-to-follow-up is to oversample specific subgroups such as those with higher comorbidity or higher risk of mortality. 50 Third, most of the studies we reviewed were relatively small, ranging from 10 to 217 (median 52) participants. This is of particular importance due to the heterogeneity of HNC survivors that receive a range of treatments with physical, psychological, socioeconomic, and other late effects that differ substantially based on patient-factors, cancer-extent and treatments.…”