HypertensionThiaZIDESNCT02591628
Treatment of Hypertension In Adults With ThiaZIDES: Pragmatic Trial Pilot Study
A study testing HCTZ prescription conversion to chlorthalidone in people with Hypertension, run by HealthPartners Institute at 2 sites in United States.
Trial summary
This proposed pilot study will test methods and feasibility for a large pragmatic clinical trial comparing two inexpensive, first-line drugs for treating high blood pressure to determine if one is superior in preventing serious cardiovascular events and death. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Hypertension
- What is being tested?
- HCTZ prescription conversion to chlorthalidone
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 2,027 participants
- Where
- 2 sitesUnited States
- Study dates
- Aug 2015to Jul 2017
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adults 18 years and older
- Hypertension diagnosis (ICD-9 401.x)
- Current prescription for hydrochlorothiazide (HCTZ), 12.5-50 mg/day as a single-agent (not part of a fixed-dose combination drug)
- No history of intolerance to chlorthalidone (CTD)
- No known low levels of sodium (<135 mEg/L (milliequivalents per liter)) or potassium (<3.5 mEg/L)
- English speaking
Who cannot join
- Physician deems patient inappropriate for switching HCTZ to CTD
- Patient refuses the switch prior to intervention
Trial locations and contacts
2 sites in 1 country.
United States2 sites
HealthPartners Institute for Education and Research
Bloomington, Minnesota, 55105
Kaiser Permanente Center for Health Research
Portland, Oregon, 97227
About this study
This proposed pilot study will test methods and feasibility for a large pragmatic clinical trial comparing two inexpensive, first-line drugs for treating high blood pressure to determine if one is superior in preventing serious cardiovascular events and death. It will develop and test novel approaches to conducting trials that will be faster, less expensive, and more realistic by being embedded in a typical practice setting and using advanced health information technology.
Read the detailed description
For several decades, U.S. hypertension treatment guidelines have recommended a low-dose diuretic such as hydrochlorothiazide (HCTZ) or chlorthalidone (CTD) as initial monotherapy in a stepped-care approach or as part of an initial two-drug combination. In numerous large clinical trials, CTD-based regimens have significantly reduced rates of cardiovascular events such as stroke, heart failure, and cardiovascular mortality compared with placebo, usual care, or active comparators. In contrast, few outcome studies have compared HCTZ-based regimens with other treatments, and they have generally found HCTZ to be less effective than non-thiazide comparators in preventing cardiovascular events. The two drugs have never been compared directly in a large trial. Despite the empirical evidence favoring CTD, HCTZ is much more widely used in clinical practice. The proposed R34 is a pilot study conducted in two large integrated health systems to test methods and feasibility for an eventual pragmatic randomized trial comparing the effectiveness of HCTZ and CTD for preventing cardiovascular events and mortality. Using a cluster-randomized design, investigators will allocate 40 primary care physicians and their adult hypertensive patients who currently use HCTZ (N=2,000) to either convert HCTZ users to CTD (intervention group) or to continue HCTZ (usual care group). The pilot study and planned full-scale trial will use existing health care infrastructure and electronic health records to identify eligible study subjects, distribute study medication, and collect operational and outcomes data. For this pilot study, Aim 1 will document that the intervention is delivered as intended. Aim 2 will compare safety in intervention and usual care patients. Aim 3 will refine the pilot study design and identify critical factors for intervention success using a mixed-methods approach. Aim 4 will refine estimates of sample size. Finally, Aim 5 will determine the costs of ascertaining outcomes and estimate per-participant costs for the full-scale trial. The pilot study will produce data that are necessary and sufficient to inform the planning of a full-scale trial comparing CTD and CTZ and will advance the development of methods for pragmatic trials.
- Conditions
- Hypertension
- Being tested
- HCTZ prescription conversion to chlorthalidone
- Keywords
- Hypertension, Thiazide diuretics
- Medical subject headings
- Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
HCTZ prescription conversion to chlorthalidoneBehavioural
The intervention is simply a prescription conversion and the main outcome is whether or not patients accept the conversion and treatment with chlorthalidone.
| Study group | Role | What they receive |
|---|---|---|
| Intervention | Active comparator | Intervention is HCTZ prescription conversion to chlorthalidone. Intervention patients are defined as patients of physicians randomized to "intervention." All these patients will have their current prescription of hydrochlorothiazide (HCTZ) switched to an equipotent dose of Chlorthalidone. These patients can choose to decline this intervention, and will be followed for 9 months with no other intervention to observe primary and secondary outcomes. Receives: Behavioral: HCTZ prescription conversion to chlorthalidone |
| Usual Care | No intervention | Usual care patients are defined as patients of physicians randomized to "usual care." All these patients will keep their current prescription for HCTZ and work with their physician like normal. These patients will be followed for 9 months with no intervention to compare primary and secondary outcomes to the intervention group. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Conversion to chlorthalidone, number of patients with primary fills
We will observe pharmacy claims to assess whether intervention patients filled their first prescription for chlorthalidone (primary adherence)
Measured: 3 months
Conversion to chlorthalidone, number of participants with secondary fills
We will observe pharmacy claims to assess whether intervention patients who filled their first chlorthalidone prescription also filled their subsequent prescription (secondary adherence)
Measured: 9 months
Secondary outcomes (5)
Blood pressure
Systolic and diastolic blood pressure measures, as documented in electronic health record
Measured: 9 months
Hypertension drugs
Use of anti-hypertensive drugs in addition to hydrochlorothiazide or chlorthalidone, as documented in pharmaceutical claims
Measured: 9 months
Electrolyte levels
Sodium and potassium levels, as documented in electronic health record
Measured: 9 months
Renal function
Kidney function lab values (including epidermal growth factor receptor (eGFR) and creatinine), as documented in electronic health record
Measured: 9 months
Safety outcomes
Hypotension with fainting (over-treatment), hypertensive crisis (under-treatment) and other clinical outcomes related to safety of hypertension treatment
Measured: 9 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Oct 2015 (estimated)
- Study startAug 2015
- Primary completionJul 2017
- Study completionJul 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypertensionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 2,027 participants (actual)
Sponsor and investigators
- Lead sponsor
- HealthPartners Institute
- Sponsor type
- University, hospital or other
- Collaborators
- Kaiser Permanente
- Responsible party
- Sponsor
- Investigators
- Karen L Margolis, MD, MPH, Principal investigator, HealthPartners InstituteStephen P Fortmann, MD, Principal investigator, Kaiser Permanente
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02591628
- Sponsor's protocol ID
- R34HL119790
- Acronym
- ThiaZIDES
- Status last verified
- Jan 2017
- First submitted
- 25 Sep 2015
- Last updated
- 11 Oct 2017
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 11 Oct 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Treatment of Hypertension In Adults With ThiaZIDES: Pragmatic Trial Pilot Study
- ClinicalTrials.gov ID
- NCT02591628
- Acronym / sponsor ID
- ThiaZIDES / R34HL119790
- Conditions
- Hypertension
- Keywords
- Hypertension, Thiazide diuretics
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 2,027 participants (actual)
- Lead sponsor
- HealthPartners InstituteUniversity, hospital or other
- Collaborators
- Kaiser Permanente
- Study start
- Aug 2015
- Primary completion
- Jul 2017 (actual)
- Study completion
- Jul 2017 (actual)
- First posted
- 29 Oct 2015 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This proposed pilot study will test methods and feasibility for a large pragmatic clinical trial comparing two inexpensive, first-line drugs for treating high blood pressure to determine if one is superior in preventing serious cardiovascular events and death. It will develop and test novel approaches to conducting trials that will be faster, less expensive, and more realistic by being embedded in a typical practice setting and using advanced health information technology.
Detailed description
For several decades, U.S. hypertension treatment guidelines have recommended a low-dose diuretic such as hydrochlorothiazide (HCTZ) or chlorthalidone (CTD) as initial monotherapy in a stepped-care approach or as part of an initial two-drug combination. In numerous large clinical trials, CTD-based regimens have significantly reduced rates of cardiovascular events such as stroke, heart failure, and cardiovascular mortality compared with placebo, usual care, or active comparators. In contrast, few outcome studies have compared HCTZ-based regimens with other treatments, and they have generally found HCTZ to be less effective than non-thiazide comparators in preventing cardiovascular events. The two drugs have never been compared directly in a large trial. Despite the empirical evidence favoring CTD, HCTZ is much more widely used in clinical practice. The proposed R34 is a pilot study conducted in two large integrated health systems to test methods and feasibility for an eventual pragmatic randomized trial comparing the effectiveness of HCTZ and CTD for preventing cardiovascular events and mortality. Using a cluster-randomized design, investigators will allocate 40 primary care physicians and their adult hypertensive patients who currently use HCTZ (N=2,000) to either convert HCTZ users to CTD (intervention group) or to continue HCTZ (usual care group). The pilot study and planned full-scale trial will use existing health care infrastructure and electronic health records to identify eligible study subjects, distribute study medication, and collect operational and outcomes data. For this pilot study, Aim 1 will document that the intervention is delivered as intended. Aim 2 will compare safety in intervention and usual care patients. Aim 3 will refine the pilot study design and identify critical factors for intervention success using a mixed-methods approach. Aim 4 will refine estimates of sample size. Finally, Aim 5 will determine the costs of ascertaining outcomes and estimate per-participant costs for the full-scale trial. The pilot study will produce data that are necessary and sufficient to inform the planning of a full-scale trial comparing CTD and CTZ and will advance the development of methods for pragmatic trials.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Intervention | Active comparator | Behavioral: HCTZ prescription conversion to chlorthalidoneIntervention is HCTZ prescription conversion to chlorthalidone. Intervention patients are defined as patients of physicians randomized to "intervention." All these patients will have their current prescription of hydrochlorothiazide (HCTZ) switched to an equipotent dose of Chlorthalidone. These patients can choose to decline this intervention, and will be followed for 9 months with no other intervention to observe primary and secondary outcomes. |
| Usual Care | No intervention | –Usual care patients are defined as patients of physicians randomized to "usual care." All these patients will keep their current prescription for HCTZ and work with their physician like normal. These patients will be followed for 9 months with no intervention to compare primary and secondary outcomes to the intervention group. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Adults 18 years and older
- Hypertension diagnosis (ICD-9 401.x)
- Current prescription for hydrochlorothiazide (HCTZ), 12.5-50 mg/day as a single-agent (not part of a fixed-dose combination drug)
- No history of intolerance to chlorthalidone (CTD)
- No known low levels of sodium (<135 mEg/L (milliequivalents per liter)) or potassium (<3.5 mEg/L)
Key exclusion criteria (2 listed)
- Physician deems patient inappropriate for switching HCTZ to CTD
- Patient refuses the switch prior to intervention
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| HCTZ prescription conversion to chlorthalidoneThe intervention is simply a prescription conversion and the main outcome is whether or not patients accept the conversion and treatment with chlorthalidone. | Behavioural | Intervention |
Primary outcome
Conversion to chlorthalidone, number of patients with primary fills
Time frame: 3 months
We will observe pharmacy claims to assess whether intervention patients filled their first prescription for chlorthalidone (primary adherence)
Conversion to chlorthalidone, number of participants with secondary fills
Time frame: 9 months
We will observe pharmacy claims to assess whether intervention patients who filled their first chlorthalidone prescription also filled their subsequent prescription (secondary adherence)
5 secondary outcomes
Blood pressure
Time frame: 9 months
Hypertension drugs
Time frame: 9 months
Electrolyte levels
Time frame: 9 months
Renal function
Time frame: 9 months
Safety outcomes
Time frame: 9 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Oct 2017.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Karen L Margolis, MD, MPH principal investigator
HealthPartners Institute
Stephen P Fortmann, MD principal investigator
Kaiser Permanente
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing HCTZ prescription conversion to chlorthalidone in people with Hypertension, run by HealthPartners Institute at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Oct 2017. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Conversion to chlorthalidone, number of patients with primary fills (time frame: 3 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Oct 2017.