Towards HOMe-based Albuminuria Screening: an Implementation Study Testing Two Approaches (THOMAS)

Dutch Kidney Foundation, E-Zorg B.V. / KPN Health, Healthy.io Ltd., Hessels+Grob, Copernicus Interchange Technology B.V., Amphia Hospital

Chronic Kidney Disease (CKD) is a worldwide major public health problem that is associated with an increased incidence of kidney failure and cardiovascular events, that lead a high burden for affected patients and high costs for society. Symptoms of CKD occur late, when kidney function drops to below 30%. At that time preventive measures will have only limited efficacy. Protein excretion in urine has increasingly been recognized as early marker of CKD, and is often associated with high blood pressure, diabetes, and/or high cholesterol levels. These are all important risk factors for progression of kidney and cardiovascular disease. Population screening for urinary protein loss could detect a considerable number of subjects with yet unknown risk factors for progressive kidney and cardiovascular disease who can benefit of early intervention. However, there is no validated method for population screening yet. The aim is to to develop a home based population screening for elevated urinary protein loss. Two screening methods will be investigated, and yield and cost-effectiveness of these screening methods will be evaluated

Chronic kidney disease (CKD) is a worldwide major public health problem that is associated with an increased incidence of kidney failure and cardiovascular disease (CVD). To tackle this burden, screening for CKD among the general population could be beneficial to allow early detection and treatment. In the last decades, elevated albuminuria has increasingly been recognized as an early marker of generalized vascular endothelial damage, that predicts CKD and CVD progression. It has been estimated that approximately 6% of the general population has elevated albuminuria, and that the majority of these subjects are not known yet with this abnormality. Among these subjects, many have hypertension, hyperlipidemia, diabetes and/or impaired kidney function, that often is also not known yet. Early detection of elevated albuminuria may be important because it gives the opportunity to invite subjects that test positive for further screening for CKD and CVD risk factors. Thus these risk factors for CKD and CVD progression could be treated in an early stage. Population screening for albuminuria could be justified according to the WHO criteria of Wilson and Jungner , because CKD has important consequences for subjects, the course of the disease is initially symptomless, and there are treatment methods available. However, implementation research to validate screening the general population for albuminuria and related health consequences is lacking, as are cost-effectiveness studies. In the current study the aim is to develop a home-based screening technique for detecting elevated albuminuria. Two screening methods will be investigated, and yield and cost-effectiveness of these screening methods will be evaluated

albuminuria, chronic kidney disease, cardiovascular disease, population screening, home based, e-Health, app, hypertension, diabetes mellitus, hypercholesterolemia

Group A will receive an invitation for home based albuminuria screening using a more conventional urine collection device (known as "Peespot Test").

Group B will receive an invitation for home based albuminuria screening using an app (internet application) and an ACR dipstick test (known as "ACR| EU Test").

The participant will receive the PeeSpot urine collection device (Hessels+Grob B.V., Deventer, The Netherlands), which consists of a holder containing a urine collection pad (consisting of hygroscopic material containing). The holder can be placed back into the tube and can be easily sent to the laboratory by mail. In this urine, albumin, creatinine, and the ACR will be measured in the laboratory of the Amphia hospital.

The participant will receive the ACR | EU test kit (Healthy.io Ltd, Tel-Aviv- Yafo, Israel), which consists of a urine test strip, a urine cup, a color calibrator and instruction to download a smartphone application. The participants have to download the smartphone application according to the instructions included in the kit. Results will be directly shown to the participant in the app.

Participation rate of the screening (i.e. home-based screening, elaborate screening and overall screening program)

The participation rate is defined as the number of persons completing the albuminuria screening (i.e. returning the first PeeSpot urine device or scanned the first ACR | EU urine test strip with use of the app, and in case of an ACR >30 mg/g in this initial test, also completing the a confirmatory albuminuria screening tests), elaborate screening and overall screening program relative to the invited number of individuals.

These are twofold. First, the yield of the home-based screening is defined as the number of persons who test positive for albuminuria (at least 2 tests positive) relative to the number of persons participating in the corresponding arm (=per-protocol analysis) and of all invited persons in the corresponding arm (intention-to-screen analysis). Second, the yield of the elaborate screening is defined as the number of subjects with increased albuminuria (defined as ACR >30 mg/g) with newly diagnosed and/or poorly controlled CVD and CKD risk factors. These risk factors, which will be assessed during the elaborate screening, include hypertension, diabetes mellitus, hyperlipidemia, impaired kidney function.

Number of persons completing the complete study (ACR testing, elaborate screening when invited, and visiting GP when recommended) relative to the number of referred individuals.

Information on (differences in) characteristics of the responders of the two screening methods (PeeSpot vs. ACR | EU) including differences in age, sex, educational level, estimated social economic status (based on data of Statistics Netherlands, providing estimated social economic status based on postal codes), medication use, and history of disease

Information on (differences in) characteristics of the non-responders of the two screening methods (PeeSpot vs. ACR | EU) including differences in age, sex, and estimated social economic status.

Usability of both tests assessed by questionnaire in the participants with a confirmed positive test and in a subgroup of participants with a negative test.

Evaluate whether the subjects who participated the elaborate screening and in which abnormalities were found (hypertension, diabetes, hypercholesterolemia, impaired renal function) did visit their general practitioner for start of appropriate treatment (lifestyle advice and/or medication).

Information on rate of false-negative and -positive tests for both screening methods (PeeSpot vs. ACR | EU).

To investigate which cut-off value of albuminuria should be used in the screening to render the most effective screening.

The role of health literacy (assessed by questionnaire) in participating in the screening program and by obtaining appropriate treatment by the GP.

Inclusion Criteria: Age 45 to 80 years. Living in the municipality of Breda, The Netherlands. Not institutionalised. Exclusion Criteria: Younger than 45 years or older than 80 years. Not living in the municipality of Breda, The Netherlands. Institutionalised. A random sample of 15.032 subjects will be drawn from the population aged 45-80 years from the municipality of Breda by the Dutch Central Bureau for Statistics (CBS).