Documentation:Cvdcalculator

What does CVDcalculator do?

DiabetesMedChoice is an interactive decision support tool to assess individualized prognosis and potential impact of medication for patients with type 2 diabetes. It is not intended for use in pediatric patients, or in adults with type 1 or gestational diabetes. DiabetesMedChoice is divided into 3 steps designed to emulate the process of patient assessment, consultation, and documentation at the point of care.

Step 1: The clinician enters patient information into a validated clinical prediction model (called RECODe) to estimate their risk of diabetes-related outcomes. The evidence behind this model is summarized and referenced on this page.

Step 2 involves selecting among treatment options to manage type 2 diabetes or its complications. Each of these options has been evaluated in at least one high-quality randomized controlled trial; this evidence is summarized below.

Step 3 illustrates the estimated impact on diabetes-related outcomes, potential side-effects, and other considerations from adding the options selected in Step 2. Risk is presented as an absolute risk (%) with and without the therapy selected in Step 2 on a bar chart.

How do I use CVDcalculator?

Step 1

Input patient data for sex, age, race, current medications, medical history, and clinical information such as blood pressure and labs.
This information is automatically entered into the model and instantly updates the risk estimates in Step 3.

Step 2

Select from the available drug therapy options. Any drugs that the patient is already taking as selected in Step 1 will be highlighted in green and not selectable again in Step 2.
You can filter treatment options based on a specific outcome of interest using the 'Filter options by outcomes' dropdown menu.

Step 3

View the patient's current risk based on input in Step 1 and risk with the addition of therapies selected in Step 2, as well as possible side-effects and other considerations from the therapies selected in Step 2.
The relative risk reductions for each diabetes-related outcomes are also shown. If you select multiple options, the cumulative relative benefit will be shown based on the assumption that the benefits of the different treatments are additive.

Step 1: Why was RECODe chosen to estimate risk of diabetes-related outcomes?

A variety of clinical prediction models (also known as "risk scores" or "risk calculators") have been developed to predict outcomes in people with type 2 diabetes, each with their own strengths and limitations. To identify the best risk scores to use in our decision aid, we performed a targeted search of existing diabetes guidelines (http://guidelines.diabetes.ca/cpg, https://diabetesjournals.org/care/issue/45/Supplement_1) and PubMed (to December 2021) for systematic reviews and validation studies of clinical prediction models in patients with type 2 diabetes. Specifically, we considered clinical prediction models based on the following factors:

Evaluated diabetes-related outcomes, including death, cardiovascular complications (e.g. myocardial infarction, stroke, heart failure), and microvascular complications (nephropathy, neuropathy, and retinopathy);
Incorporated variables that are readily available in clinical practice;
Had been externally validated in at least 1 study; and
Demonstrated good predictive power based on discrimination and calibration.

RECODe was found to have the best predictive power among clinical prediction models for cardiovascular and kidney outcomes in patients with type 2 diabetes in a 2021 systematic review and meta-analysis.

RECODe (development & validation; external validation)
Outcomes	Definition	Discrimination: C-statistic from external validation	Calibration	Note
Death	-	0.71-0.81	Good	-
Heart attack/stroke	Fatal or non-fatal myocardial infarction or stroke	0.73-0.77	Good/underestimated at lower risk	Outperformed UKPDS risk calculator & ACC/AHA Pooled Cohort Equations
Heart failure	Symptomatic heart failure (regardless of ejection fraction)	0.73-0.80	Good/over-predicted at lower risk	Outperformed UKPDS risk calculator
Kidney failure	Need for dialysis, or serum creatinine concentration >290 umol/L	0.78-0.91	Not reported	Outperformed UKPDS risk calculator
Severe vision loss	<20/200 visual acuity by Snellen chart	(Internal validation only): 0.62 (0.60-0.64)	Good
Neuropathy	Pressure sensation loss	0.69 (0.63-0.74)	Good

Step 2: How were therapies chosen and where do the estimates of benefits and side-effects come from?

We selected pharmacological interventions for inclusion in DiabetesMedChoice based on a comprehensive review of guidelines, reviews, as well as consultation with content experts. Treatments are sub-categorized as (1) general treatment strategies (i.e. intensity of blood glucose or blood pressure control), (2) specific glucose-lowering medications, and (3) non-glucose-lowering medications intended to reduce one or more diabetes-related outcomes. The estimates of benefits and side-effects come from randomized controlled trials (RCTs) and meta-analyses of RCTs. With DiabetesMedChoice, a patient’s individualized benefit is estimated by applying the cumulative relative risk reduction of all treatments selected in Step 2 to the estimated risk calculated using RECODe in Step 1. For side-effects, adverse events that were statistically significantly higher with therapy in RCTs are reported as absolute risk increases.

Relative risks (RR) for overall cardiovascular disease in primary prevention
Treatment	ASCVD	References
Physical activity	0.83 ⁽¹⁾	¹ J Am Heart Assoc. 2016;5:e002495
Mediterranean Diet vs Low fat	0.70⁽¹⁾	¹ N Engl J Med 2018; 378:e34 DOI: 10.1056/NEJMoa180038
Omega 3 supplements	1⁽¹⁾	¹Cochrane Database of Systematic Reviews 2018, Issue 7. Art. No.: CD003177
Blood pressure reduction if >160mm Hg	0.78⁽¹⁾	¹JAMA Intern Med. 2018;178(1):28-36
Blood pressure reduction if BP 140-159mm Hg	0.88⁽¹⁾	¹JAMA Intern Med. 2018;178(1):28-36
Blood pressure reduction if <140mm Hg	1⁽¹⁾	¹JAMA Intern Med. 2018;178(1):28-36
Statins if >65 years	0.82⁽¹⁾	¹Drugs & Aging volume 32, pages 649–661 (2015
Statins overall	0.74⁽¹⁾	¹Am Heart J 2019;210:18-28
Fibrates	0.84⁽¹⁾	¹Cochrane Database of Systematic Reviews 2016, Issue 11. Art. No.: CD009753
Fibrates added to statins	1⁽¹⁾	¹Cochrane Database of Systematic Reviews 2016, Issue 11. Art. No.: CD009753
Ezetimibe	NA	¹No data in primary prevention
Aspirin	0.89	¹JAMA. 2019;321(3):277-287. doi:10.1001

NA: No RCT data available. For a given outcome, an intervention with no RCT data available is given RR=1.00, conservatively assuming no positive or negative effect of the intervention on that particular outcome.

Adverse effects and other considerations by treatment
Treatment	Adverse effects (absolute % increase)	References	Cost	Routine	Caution & Others
Physical activity	-		Varies based on which medications are used	Varies based on which medications are used
Mediterranean Diet vs Low fat
Omega 3 supplements
Blood pressure medications
Statins	Muscle pain (+0.3%) ^(25-28) Rhabdomyolysis (+0.01%) ⁽²⁵⁾ Elevated liver enzymes (+1%) ⁽²⁷⁾ New diabetes (+0.5%) ⁽²⁷⁾	²⁵ Am Heart J 2014;168:6-15 ²⁶ STOMP. Circulation 2013;127:96-103, ²⁷ Eur J Prev Cardiol 2014;21:464-74, ²⁸ NEJM 2016;374:2021-31	About $30 for 90 days ($120/year)	One pill once a day
Fibrates
Ezetimibe	None ⁽²⁰⁾		About $30 for 90 days ($120/year)	One pill once a day
Aspirin	Major bleed (+1%) ⁽¹⁹⁾		About $40/year	One pill once a day	Consider taking with food to minimize stomach upset.

Why are some medications listed in both Step 1 and Step 2?

Medications that are included in Step 1 are used directly by the risk calculator to estimate current risk. On the other hand, the effect of medications listed in Step 2 is based on applying the relative risk reduction derived from randomized controlled trials to the current risk. As a result, for example, the effect of receiving a statin at baseline can be different from the estimated effect of adding a statin "during the visit".

How were costs estimated? (last updated 28 Feb 2020)

Cost estimates are based on Canadian dollars (CAD), updated annually or more frequently as needed, and estimated using the following websites:

https://acfp.ca/wp-content/uploads/2019/02/ACFPPricingDoc2019.pdf
http://www.medi-mouse.com/drugfind.php
https://www.studybuffalo.com/tools/drug-price-calculator/

Quality checklist: International Patient Decision Aid Standards instrument (IPDASi)


Criteria	Answer
INFORMATION: Providing information about options in sufficient detail for making a specific decision	8/8
1. Describes the health condition or problem for which the index decision is required	Yes
2. Describes the decision that needs to be considered	Yes
3. Describes the options available for the decision	Yes
4. Describes the natural course of the health condition or problem if no action is taken	Yes
5. Describes the positive features (benefits or advantages) of each option	Yes
6. Describes negative features (harms, side-effects or disadvantages) of each option	Yes
7. Makes it possible to compare the positive and negative features of the available options	Yes
8. Shows the negative and positive features of options with equal detail	Yes
PROBABILITIES: Presenting outcome probabilities	7/8
1. Provides information about outcome probabilities associated with the options	Yes
2. Specifies the defined group of patients for which the outcome probabilities apply	Yes
3. Specifies the event rates for the outcome probabilities (in natural frequencies)	Yes
4. Specifies the time period over which the outcome probabilities apply	Yes
5. Allows the user to compare outcome probabilities across options using the same denominator and time period	Yes
6. Provides information about the levels of uncertainty around event or outcome probabilities	No
7. Provides more than one way of viewing the probabilities (e.g. words, numbers & diagrams)	Yes
8. Provides balanced information about event or outcome probabilities to limit framing biases	Yes
VALUES: Clarifying and expressing values	3/4
1. Describes the features of options to help patients imagine what it is like to experience the physical effects	Yes
2. Describes the features of options to help patients imagine what it is like to experience the psychological effects	Yes
3. Describes the features of options to help what it is like to experience the social effects	Yes
4. Asks patients to think about which positive and negative features of the options matter most to them	No (role of the clinician at the point of care)
DECISION GUIDANCE: Structured guidance in deliberation and communication	1/2
1. Provides a step-by-step way to make a decision	Yes
2. Includes tools like worksheets or lists of questions to use when discussing options with a practitioner	No
DEVELOPMENT: Using a systematic development process	2/6
1. The development process includes finding out what patients need to prepare them to discuss a specific decision	Yes
2. The development process included finding out what health professionals need to prepare them to discuss a specific decision with patients	Yes
3. The development process included expert review by patients not involved in producing the decision support technology	Pending
4. The development process included expert review by health professionals not involved in producing the decision support technology	Pending
5. Field tested with patients who were facing the decision	Pending
6. Field tested with practitioners who counsel patients who face the decision	Pending
EVIDENCE:	4/4
1. Provides citations to the studies selected	Yes
2. Describes how research evidence was selected or synthesized	Yes
3. Provides a production or publication date	Yes
4. Provides information about the proposed update policy	Yes
DISCLOSURE:	2/2
1. Provides information about the funding used for development	Yes
2. Includes author/developer credentials or qualifications	Yes
PLAIN LANGUAGE:	0/1
1. Reports readability levels	Pending
EVALUATION:	0/2
1. Evidence that the decision aid improves the match between the features that matter most to the informed patient and the option that is chosen	No
2. Evidence that the patient decision aid helps patients improve their knowledge about options’ features	No

Developed by:

This tool was developed by the DiabetesMedChoice Development Panel:

Ricky D. Turgeon BSc(Pharm), ACPR, PharmD (ricky.turgeon@ubc.ca)

Assistant Professor – Greg Moore Professor in Clinical and Community Cardiovascular Pharmacy, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC

Clinical Pharmacy Specialist - PHARM-HF, St. Paul's Hospital, Vancouver, BC

James McCormack BSc, BSc(Pharm), PharmD

Professor, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC

Funding: None.

Conflict of interest: Drs. Turgeon and McCormack declared no conflict of interest.

Peer reviewed by:

Version history

Version 1.0 (last update: January 2022 | last evidence review December 2021)

Update policy: Update at least annually in January, or more frequently as needed with availability of new evidence.