What’s a Correction Factor? The correction factor (also called “insulin sensitivity”) needs to be changed according to how much insulin you are taking. Most hospitals use low, medium, and high scales that provide doses of insulin when glucose levels exceeds 140–150 mg/dl and increase with additional glucose increments of 40–50 mg/dl ( Figure 2 ). Assess correction insulin when meal bolus insulin given:1. Correction insulin is an extra dose of insulin given to reduce high blood glucose. Note: TDD=Total daily Dose ICR=Insulin to Carbohydrate Ratio ISF=Insulin Sensitivity Factor or ICF=Insulin Correction Factor Insulin Calculation Example How to understand ICR: 500/TDD (basal and bolus combined) One of your patients with type 2 diabetes is on 20 units of Toujeo (concentrated glargine) once daily and 10 units of FIASP (aspart) three times a day with each meal. The number 1800 should work when the TDD is set correctly and the basal insulin makes up 50% of the TDD in someone with Type 1 diabetes. Others do not write out their scale; they just calculate an extra dose using their Correction Factor and add it to their baseline (usual) dose at meals. An insulin sensitivity factor (ISF) or correction factor describes how much one unit of rapid or regular insulin will lower blood glucose. 2. Add this insulin dose to ICR dose. The correction factor or insulin sensitivity can be used to make a scale for pre meal insulin doses. (CF = correction factor; C:I = carbohydrate-to-insulin ratio; TDDI = total daily dose of insulin.) The correction dose is added to, or subtracted from, the pre-meal insulin dose. A person with insulin resistance is likely to have a lower number for ISF (eg. So, you will need an additional 2 units of rapid acting insulin to “correct” the blood sugar down to a target of 120 mg/dl. E.g. MDI Test: Patient quiz to assess ISF, carb ratio, DKA prevention, hypo treatment. 16. This correction worked. Endocr Pract. Step 3: Set Y our Insulin Correction Factor. E.g. If using the ISF is difficult for a patient, consider creating a correction scale. It is individualized and based on total daily dose of insulin (TDD), as well as trial and error. This correction insulin would be given in addition to the meal bolus (insulin to cover the food). Subtract the target blood sugar from the current sugar to calculate the gap. In this situation consider a new ISF of 2 to start, as it is safer. 3, 4 or occasionally 5). an ISF of 1.5 (1 unit drops glucose 1.5 mmol/L). * First you need to add up the total amount of insulin you take in a day, your TDD (total daily dose). REFERENCE Staying on Target . Corrections after meals are often not suggested, to avoid “stacking” insulin. 3 hours since the last dose of fast-acting insulin. If ISF is 3, it will increase by approximately 3 mmol/L. Method 2 Meal Bolus + Correction Scale Adjustment. 100/TDD = ISF if using rapid insulin (the number of mmol that 1 unit drops glucose in 3-4 hours approx), 83/TDD= ISF is using regular/Toronto insulin (the number of mmol/L that 1 unit drops glucose in 3-5 hours approx), EXAMPLE ONE: Teddy, TDD 33, takes rapid insulin, 1 unit rapid insulin is expected to lower Teddy’s blood sugar by 3 mmol/L, EXAMPLE TWO: Bear, TDD 80, takes regular insulin. These are four different approaches with the same goal: correcting high blood glucose. calculating how much 1 unit of insulin will drop your blood sugar is a trial and error process, and sensitivity to insulin varies with the individual. Insulin sensitivity factor (ISF) or “correction factor” is how much one unit of insulin is expected to lower blood sugar. Yes, You Can Do it! Breakfast 12.0 mmol/L, gave meal and correction insulin, lunch 9.5 mmol/L. It is difficult to 9obtain optimal control without occasional, mild episodes of hypoglycemia. With this method people need to remember their target blood sugar level. Discuss your target levels with your health care team (see Question 1). This correction insulin would be given in addition to the meal bolus (insulin to cover the food). Change ISF from 2.0 to 3.0 as an option. For example, Tom wants to calculate his correction factor: Therefore, one unit of rapid acting insulin would lower Tom’s blood sugar by 2 mmol/L over the next 2 to 4 hours. Remember to check ketones if the blood glucose is more than 14 mmol/l and follow the sick day rules if unwell. Divide 100 by your TDD. Assess correction insulin against the ISF formula: E.g. If using mobile, turn phone sidways. See the scale below for an example of the latter. However, if required, advise to correct to a post meal target eg. What is a correction factor? Sandy has high readings using an ISF of 3. expect variations - sometimes 1 unit will lower it by more, and other times 1unit will lower it by less! There still is about 50 to 40 per cent of that dose remaining to lower blood sugars. Correction dose = (Current blood sugar -Target blood sugar) / ISF = (160-90)/ 34 = 2.1 units . Correction Factors (ISF) Your correction or insulin sensitivity factor (ISF) is how many mmol/L your BG levels drop when you take 1 unit of insulin. A Correction Factor (sometimes called insulin sensitivity), is how much 1 unit of rapid acting insulin will generally lower your blood glucose over 2 to 4 hours when you are in a fasting or pre-meal state. Correction doses may be the same for each meal, as per the scale above, or they may differ per meal based on trial and error. If your correction factor = 2, this means that 1u of insulin will decrease your blood sugar by 2 mmol/L. In order to know this factor, you need to know how much one unit of rapid-acting insulin will drop the blood sugar! My basil or background rate is 48.8 units. This is aggressive; a safer start may be an ISF of 2. This is called your Total Daily Dose (TDD). To calculate your correction factor: 1. Correction factor is 40. The CorrF or ISF (Insulin Sensitivity Factor) is how many mg/dL (or mmol/L) your glucose drops on each unit of insulin. Sliding Scale . Change ISF from 3.0 to 2.0 as an option. All rights reserved. Insulin sensitivity factor, or correction factor, refers to the number of milligrams per deciliter (mg/dL) by which blood sugar levels fall when a person takes 1 unit of insulin. This adjusts or corrects a blood glucose level that may be higher or lower than desired before a meal. Therefore, the bolus calculator needs to know how much 1 unit of insulin will lower your blood sugar. Current Blood Sugar –Target Blood Sugar = Correction Insulin Dose Correction Factor •Example: Before meal blood sugar is 200. 1. •200 –120 = 80 ÷ by 40 = 2 units of insulin to correct your high blood level. To get your total daily dose, add up all your usual meal time insulin and basal insulin. Insulin Sensitivity Factor (Correction Factor) = 1700 / TDD. Time to play with math! © Start with a BG level that is above your target (make sure its been 3-5 hours since your last meal or bolus and when you can wait 4 hours to eat.) Example:Using the Correction Factor or insulin sensitivity, Target blood sugar is 7 & glucose is 13.2 before lunch. 2008; 14(9):1095-101. If the meal insulin works when in target, next look for pre-meal readings that are above target. 2011;20(4):187-193. Insulin Sensitivity Factor. E.g. Breakfast 12.0 mmol/L, gave meal and correction insulin, lunch 3.3 mmol/L. For those with low carbohydrate diets, expect a higher % basal. Blood sugar target is 120. correction factor) Correction insulin calculated (units) Total carbohydrates (g) Food formula (carb count/ carb ratio) Food insulin calculated (units)-----Daily plan: Calculate total insulin dose • Add the number of units needed for food to the number of units needed to correct blood sugar to get your total dose of insulin (Humalog/Novolog/Apidra). Medsurg Nurs. 3. Davidson PC, et al. For a 60 gm carbohydrate meal = 60/10 = take 6 units. For creating Correction Scales, see below. A correction factor is a number, along with a target bg goal, that is used to determine the quick acting insulin dose. factor/correction factor. It is used to determine the amount of insulin to give to correct blood glucose readings that are above target. An insulin sensitivity? E.g. 2. Target blood sugar is 7 & glucose is 13.2 before lunch. Be sure to let them know this could be useful information if they had any to share. Using an Insulin Sensitivity Factor (ISF) Current glucose– target glucose / ISF = units to give to correct the high reading. 2. TDD= 50 units insulin ISF= 1700 /50 = 34 mg/dL The current premeal blood sugar is 160 mg/dL The target premeal blood sugar is 90 mg/dL. I use an insulin pump that is constantly feeding me a small amount of insulin… For example, before a meal, an adult with a correction factor of 30 (i.e., one unit of insulin lowers blood sugar by 30 mg/dl) would: Add 2.5 units to the mealtime insulin dose for a sharply rising arrow; Subtract 2.5 units from the usual insulin dose for a sharply falling arrow. For example, if 1 unit of insulin will drop your blood sugar by 25 mg/dl, then your insulin sensitivity factor is 1:25. Also recheck your TDD and basal percentage to make sure they are corr… Your insulin-to-carb ratio (also just called a “carb ratio” or “carb factor”) indicates how many grams of carbs one unit of rapid-acting insulin covers to ensure that your blood sugars stay in your desired range. An ISF of 5 may be needed in early type 1 diabetes, although high readings may often “self-correct” in those who are honeymooning and still making endogenous insulin. 2021 USING THE CORRECTION FACTOR. A “1700 rule” has been used to estimate how much 1 unit of insulin will lower glucose. Education Events for Healthcare Professionals, daily insulin dose: 8 units at breakfast, 6 units at lunch,10 at dinner and N/NPH 8 units at breakfast and 18 units at 10 pm, Total Daily Dose (TDD) = 8 + 8 + 6+ 10 + 18 = 50, some people need 1 unit of insulin for every 1 mmol/L increase in blood sugar, others need 1 unit of insulin for every 3 -5 mmol/L increase in blood sugar, 6 mmol divided by correction factor of 2 = 3 units to lower blood sugar by 6 mmol/L, baseline of 10 + 3 for correction = 13 units, therefore, the insulin dose would be 13 units with lunch, the type of meal you ate - high fat carbohydrate meal vs. high fibre, low fat carbohydrate meal, is it the type of meal that makes your blood sugars higher than usual for a longer than usual time, or, is it the type of where your blood sugars return to normal within the 2 hours, Blood glucose = 18.6 at 2 hours after breakfast, 8.6 mmol/L divided by Correction Factor of 2 = 4, 4 units will lower blood sugar by 8 mmol/L, therefore, the 2 hour correction dose would be 2 units. of 10 mmol/L. The insulin sensitivity factor is also sometimes called a “correction factor.” You need to know this number to correct a blood sugar level that’s too high. CHILDREN AND OLDER ADULTS As the prevalence of obesity in … Step 2: The Rule of 1800 There are several simple formulas for figuring this out. The ISF is usually dependent on the individual’s sensitivity to insulin. 1 unit of regular is expected to lower Bear’s sugar by 1 mmol/L. If you take the same correction bolus as you would before a meal, you may have a low blood sugar from ‘insulin stacking’! © 2021 Mount Sinai Hospital. Correction boluses are used to lower high glucose levels to the glucose target. 1 or less than 1). If needed, the ISF can change to 1 in the future. First assess if the meal insulin works when in target and no correction insulin is needed. E.g. Correction Formula, or. if an ISF is 2, the left-hand column range for blood glucose readings will increase by approximately 2 mmol/L. 19 A sensitivity, or correction, factor is calculated by dividing 1700 by the TDD. The insulin correction factor (or insulin sensitivity factor) is a bolus of insulin to bring down a higher than range blood sugar level. Correction factor: Blood glucose level – target blood glucose/correction factor = units insulin to be given – Example: BG=150 (actual) minus Target BG (100) = 50 divided by Correction factor (50) = 1 unit insulin needed. Analysis of guidelines for basal-bolus insulin dosing: basal insulin, correction factor, and carbohydrate-to-insulin ratio. A correction factor – also called insulin sensitivity factor (ISF) – helps you figure out how much insulin to give yourself to bring your high blood sugars down to the normal range without going low. The effects of correction insulin and basal insulin on inpatient glycemic control. Using the Correction Factor or insulin sensitivity. Example: If your baseline dose of insulin at breakfast is 4 units and your before breakfast blood sugar is 10.5 mmol/L, and your food and activity will be the usual, you need to take 6 units (4 units to cover your food and 2 units to correct for the high blood sugar). A ratio? Numbers between 1600 and 2200 can be used to determine the correction factor. What is my correction factor? Clients are often hesitant to report times they've corrected but missed the meal. If subsequent blood glucose readings are: -- In target after giving meal bolus AND correction insulin, the ISF is likely appropriate.-- High after giving meal bolus AND correction insulin, consider decreasing ISF number by 0.5 or 1.0. it is outside of target, you can add in a correction dose (also called an insulin sensitivity factor) to your pre-meal dose of insulin. Repeat this test until you have determined your sensitivity factor/correction factor and then repeat it one more time to confirm the results. Example. The correction factor, also known as Sensitivity Factor is the amount 1 unit of insulin will lower blood sugar. Sample correction scale: The same correction is given regardless of meal. The formula suggests an ISF of 1. To get the high blood sugar correction insulin dose, plug the numbers into this formula: Correction dose = Difference between actual and target blood glucose (100mg/dl) ÷ correction factor (50) = 2 units of rapid acting insulin. Your carb ratio is often initially set by your doctor when you are diagnosed but should be updated regularly (if needed). This split varies for those on partial-closed-loop insulin pumps due to algorithms. Correction Factor = 1800 ÷Total Daily Insulin Dose (TDD) = 1 unit of insulin will reduce the blood sugar so many mg/dl My TDD for yesterday was 85.4 units. The average adult needs approximately 1 unit of insulin for every 2 mmol increase in blood sugar, but this can vary a lot between individuals: Before meal means there has been about 4 hours or more since you last ate or took an insulin dose for carbohydrate containing food or beverage. --Low after giving meal bolus AND correction insulin, consider increasing ISF number by 0.5 or 1.0. CORRECTION DOSE This is the insulin dose you take for high blood glucose during daytime and nighttime. Correction Number. A number smaller than 1800 will work better when basal insulin doses make up less than 50% of the TDD, while a number higher than 1800 works better for those whose basal doses make up more than 50% of their TDD. An ISF of 1 (1 unit to drop 1 mmol/L) is usually not safe to start, although a very insulin resistant client may eventually require that. Correcting for a high blood sugar 2 hours after eating is using your best estimate! If you are not sure about this then please call a member of the team to discuss how to do this. My insulin sensitivity factors: B: _____ L: _____ S: _____ How to Test your ISF 1. In the example above, the pump would recommend 3 units of insulin to bring blood glucose from 175 mg/dl down to 100 mg/dl. In lean people with established type 1 diabetes, an ISF of 3-4 is not unusual. Insulin Sensitivity Factor (ISF) or Correction Dose . A person more sensitive to insulin is likely to have a larger number for ISF (eg. To correct for high blood sugars at 2 hours after a previous bolus, estimate what you would use as a correction factor and then divide by 2 – or use your insulin pump calculator! ISF=2 (meal bolus insulin is not included in this particular chart.) An ISF of 2 (1 unit to drop blood glucose 2 mmol/L) is common and would be safer to try initially, than an ISF of 1. This calculation is based on the “100 Rule”. Insulin Sensitivity Factor (ISF) 2. Correction factor (CF) = 1800 / total daily dose of insulin (1800 rule) ALTERNATE STARTING CHOICE: ... Insulin to Carbohydrate Ratio (I:C Ratio): 500/50 = 1:10 units. Time to play with math! The Insulin Correction Factor is used by the mySugr bolus calculator to calculate the amount of insulin that you need to correct high blood sugar values and bring you back to your target value. To create an Insulin Sensitivity Factor (ISF) for RAPID insulin: 100/TDD = number of mmol/L 1 … supplemental (correction) insulin regimen.8 8. At 2 hours approximately 50 to 60 per cent of your bolus is used. Add up all insulin taken in the day (long acting and rapid acting). 12 mmol at breakfast, gave correction but no meal eaten and no food bolus, by lunch was 6.5 mmol/L. Remember how your insulin works – insulin action or duration of effect. A correction factor is how much 1 unit of rapid acting insulin will lower your blood sugar. Adjust insulin for illness; Identify when to call for help; Please e-mail us with your comments and suggestions about this program. Assessing and Changing an ISF. If your blood glucose is < 30 mg/dl of your target blood glucose 4 hours after the dose, repeat the test again with a larger insulin sensitivity factor/correction factor. Assess correction insulin used alone without meal bolus:If the client took correction insulin but had no meal (no food bulus), assess if it worked. Example: 13 mmol/L – 7 mmol/L target / ISF of 2 = 3 units to correct high blood sugar . (The TDD is the total amount of insulin I take in a day. The correction dose measures the drop in your blood sugar that occurs per unit of insulin. However, you should keep in mind: it may need to change as your baseline dose changes. Step 2: The Rule of 1800 There are several simple formulas for figuring this out. The insulin correction factor (or insulin sensitivity factor) is a bolus of insulin to bring down a higher than range blood sugar level. Insulin Dose Adjustment Modules. The insulin correction factor (sometimes called an insulin sensitivity factor) is used to calculate the amount of insulin you need to bring your blood glucose into target range. 4. In order to know this factor, you need to know how much one unit of rapid-acting insulin will drop the blood sugar! There are apps (see below) that work as an insulin calculator. 5. Then divide by the Correction (sensitivity) Factor to calculate the correction dose. As with any insulin formula, expect that results can vary at times. CLINICAL NUTRITION. ISF values, particularly in insulin pump therapy, may also be developed using fractions e.g. Current glucose– target glucose of 10 / ISF = units to give to correct the high reading after a meal. Johnston JA, Van Horn ER. Current glucose– target glucose / ISF = units to give to correct the high reading, Example: 13 mmol/L – 7 mmol/L target / ISF of 2 = 3 units to correct high blood sugar. The correction factor, or Insulin Sensitivity Factor (ISF), specifies how much insulin is needed to correct blood glucose back to the target range. Your Insulin Adjustment Workbook. Diabetes Educators Calgary, Continuous Glucose Monitoring (CGM) Benefits and Challenges. Correction factor / Insulin sensitivity If the blood glucose level is above the target range pre-meal additional insulin will be needed to bring it back into the target range. Worked example .