Distal Renal Tubular Acidosis (dRTA) is a tubular disorder with a primary defect of urinary acidification and acid excretion in the collecting duct system that can be either genetic or acquired. Cystinuria is an inherited disorder of the dibasic amino acid transport system in the proximal tubule and the small intestine.
Until now treatment options are very limited, not specific and not designed for patients with dRTA and cystinuria, but new therapies are in development and may soon be available.
Using collected electronic health data from general practices and hospital admissions, we aim to estimate the number of individuals (adult and children) who are currently experiencing dRTA and cystinuria. After identifying the patients, we will focus on their pathways in the healthcare system, by studying medication prescriptions, hospitalisations, referrals to specialists and specialist visit as well as hospitalizations, and will estimate the financial burden of medical care associated with these patients.
Since no treatment is specific for these conditions, the findings of our study are expected to estimate the unmet needs and the future access landscape and identify the strategic solutions to access challenges with payer during the launch of new medicines.
The objectives of the study are (1) to estimate the prevalence of children and adults suffering from dRTA or cystinuria; (2) to study patient pathways; (3) and to evaluate the financial burden of medical care of these two conditions.
Using the Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics (HES) databases, we will study the patients with a coded general practitioner (GP) diagnosis of dRTA and those with a coded diagnosis of cystinuria. Genetic dRTA and cystinuria are well diagnosed but acquired dRTA may be misdiagnosed since patients are suffering from various associated syndromes and/or several conditions with similar symptoms. These patients need to be studied in terms of treatment and pathways to be sure of the accuracy of the estimates.
The main analyses will consist of descriptive analyses to evaluate the prevalence of the two conditions in adult and children populations. Resource use for both inpatient (number of stays and length of stay, etc.) and outpatient (prescription items, referrals visits, etc.) will be estimated for these patients.
Finally, these estimates will be scaled up to the entire population and will be used to evaluate the financial burden of medical care of dRTA and cystinuria in the UK.
The first outcomes of interest will be GP diagnosis of dRTA and cystinuria.
Then, various diagnosis codes will be studied as well as drug utilisation and referrals to specialist to identify additional patients possibly suffering from these two conditions but without a formal diagnosis. The codes related to associated syndromes or diseases with similar symptoms. The list of codes has been reviewed by a clinical expert in dRTA and cystinuria.
The identification of the additional patients will be further validated by clinical expert opinion.
Once these patients have been identified, age and gender will be the variables of interest to estimate the global prevalence.
In a second step of our study, the resource use (hospitalisations, laboratory tests, specialist's referrals...) will be the outcomes of interest.
Monique Martin - Chief Investigator - Not from an Organisation
Lucile Marie - Corresponding Applicant - Syneos Health Consulting Inc (formerly inVentiv)
Florence Bianic - Collaborator - Syneos Health Consulting Inc (formerly inVentiv)
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient