Protocol for a randomized study assessing the feasibility of home-based albuminuria screening among the general population: The THOMAS study

Abstract

Background Chronic kidney disease (CKD) is a rising public health problem that may progress to kidney failure, requiring kidney replacement therapy. It is also associated with an increased incidence of cardiovascular disease (CVD). Because of its asymptomatic nature, CKD is often detected in a late stage. Population screening for albuminuria could allow early detection of people with CKD who may benefit from preventive treatment. In case such screening is performed in a general practitioner (GP) setting, this will result in relatively high costs. Home-based screening might be an effective and cost-effective alternative. Aim The THOMAS study (Towards HOMe-based Albuminuria Screening) is designed to prospectively investigate two methods for home-based population screening for increased albuminuria to detect yet undiagnosed CKD and risk factors for progression and CVD. Methods This investigator initiated, randomized population-based study will include 15.000 individuals aged 45–80 years, who will be randomly assigned to be invited for a home-based screening test for albuminuria with a more conventional urine collection device or an innovative smartphone application. If the test result is positive upon confirmation (i.e., elevated albuminuria), participants are invited to a central screening facility for an elaborate screening for CKD and CVD risk factors. Participants are referred to their GP for appropriate treatment, if abnormalities are found. Primary endpoints are the participation rate, yield, and cost-effectiveness of the home-based screening and elaborate screening. Conclusions The THOMAS study will evaluate the effectiveness and cost-effectiveness of home-based albuminuria screening in the general population for the early detection of CKD and CVD risk factors. It will provide insight into the willingness to participate in population screening for CKD and into the compliance of the general population to a corresponding screening protocol and compliance to participate. Thus, it may help to develop an attractive novel screening strategy for the early detection of CKD. Trial registration ClinicalTrials.gov, registration number NCT04295889, registered 05 March 2020. https://www.google.com/search?client=firefox-b-d&q=NCT04295889.

Participation rate and yield of two home-based screening methods to detect increased albuminuria in the general population in the Netherlands (THOMAS): a prospective, randomised, open-label implementation study

“…Due to the high number of falsepositive tests in participants who used the smartphone application method (table 3), the results of the elaborate screening at the central screening facility of these participants are not considered to reflect the characteristics of a population with increased albuminuria that we aimed to identify in the current study. The CKD and cardiovascular disease risk factors found in individuals assigned to the smartphone application method who completed elaborate screening (n=142) are therefore only shown in the appendix (pp [15][16][17].…”

“…The analytical approach for the study's sample size has been published previously. 16 The sample size was calculated to be able to detect a significant difference between both screening methods for finding a participant with at least one newly diagnosed risk factor. The sample size was calculated on the basis of several assumptions: a participation rate of 47•5% for the UCD method and 52•5% for the smartphone application method; that 8% of the participants would have elevated ACR, of whom 90% will have confirmed elevated ACR by the confirmatory tests; a participation rate in the elaborate screening of 90%; and 71% of participants using the UCD method and 51% of participants using the smartphone application method would have a newly diagnosed risk factor for cardio vascular disease or CKD.…”

“…To define the presence of risk factors during the elaborate screening, definitions were used in accordance with prevailing national guidelines for Dutch general practitioners or in accordance with international guidelines when Dutch guidelines were not available, as described previously 16 (appendix p 5). For the UCD method, urinary albumin concentrations were measured by immunoturbidimetry and urinary creatinine concen trations were measured enzymatically in a central laboratory at Amphia Hospital on a Cobas c502 analyser (Roche Diagnostics, Almere, Netherlands).…”

“…The study protocol and methods have been published elsewhere. 16 The study protocol was approved by the Medical Ethics Committee of the University Medical Center Groningen (Groningen, Netherlands; 2018.687).…”

Cost-effectiveness of home-based screening of the general population for albuminuria to prevent progression of cardiovascular and kidney disease

“…The model was informed by the Towards HOMe-based Albuminuria Screening (THOMAS) study ( NCT04295889 ). 20 This randomized study evaluated the effectiveness of two home-based albuminuria screening strategies in 15,074 Dutch individuals aged 45–80. 21 Individuals were randomized (1:1) to receive at home a urine collection device to collect some urine, and whereafter this device was sent by regular post to a central laboratory for albumin:creatinine ratio (ACR) measurement or a package containing material and instructions to download a smart-phone app (App) to measure the ACR with a dipstick method at home.…”