Deficiency Writing for Third Party Reviewers:

Examples

Hongying (Helen) Jiang, PhD, RAC

Center for Devices and Radiological Health

U.S. Food and Drug Administration
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Practice Makes Perfect

Applying concepts with examples helps 

reinforce learning principles in any area
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1. Deficiency Writing for Third Party Reviewers

2. Examples and Knowledge Checks

How to Use this Presentation
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• Review deficiency writing using four-part 

harmony format

• Identify aspects of four-part harmony in a good 

example/deficiency

• Complete knowledge checks to identify missing 

parts in incomplete deficiencies

Learning Objectives
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Disclaimers

• Deficiencies and examples listed are to illustrate 

teaching principles only

• Does not intend to imply or establish regulatory 

policy with specific device examples

• Review applicable FDA laws, regulations and 

guidance for cross-cutting or specific matters
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Four-Part Harmony

1. What was provided

2. What is deficient

3. Why it is needed

4. What is needed
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A Good Example

• Include all four parts in a deficiency

• Look for each part in the full deficiency
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The Full Deficiency

You have proposed that your powered muscle stimulator is intended to be 

used in the home environment by lay users. However, you have only included 

professional labeling intended for healthcare providers. The FDA recommends 

in our “Guidance on Medical Device Patient Labeling” that you provide patient 

labeling for your device since you intend for patients to operate the device. 

Therefore, please submit patient labeling that explains your device and 

includes directions for use, study design and results, and any additional 

relevant information. Please use clear language and terms understandable by 

the lay person. Please also include a glossary of all relevant medical terms and 

ensure that all appropriate contraindications, warnings, and precautions from 

the professional labeling are conceptually the same, but are rewritten for 

understanding by the lay person. 
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Part 1. What was provided

You have proposed that your powered muscle 

stimulator is intended to be used in the home 

environment by lay users.
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Part 2. What is deficient

However, you have only included professional 

labeling intended for healthcare providers.
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Part 3. Why it is needed

The FDA recommends in our “Guidance on 

Medical Device Patient Labeling” that you provide 

patient labeling for your device since you intend 

for lay persons to operate the device.
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Part 4. What is needed

Therefore, please submit patient labeling that explains 

your device and includes directions for use, study design 

and results, and any additional relevant information. 

Please use clear language and terms understandable by 

the lay person. Please also include a glossary of all 

relevant medical terms and ensure that all appropriate 

contraindications, warnings, and precautions from the 

professional labeling are conceptually the same, but are 

rewritten for understanding by the lay person. 
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Example 2: Full Deficiency (in color)

You have proposed that your powered muscle stimulator is intended to be 

used in the home environment by lay users. However, you have only included 

professional labeling intended for healthcare providers. The FDA recommends 

in our “Guidance on Medical Device Patient Labeling” that you provide patient 

labeling for your device since you intend for lay users to operate the device. 

Therefore, please submit patient labeling that explains your device and 

includes directions for use, study design and results, and any additional 

relevant information. Please use clear language and terms understandable by 

the lay person. Please also include a glossary of all relevant medical terms and 

ensure that all appropriate contraindications, warnings, and precautions from 

the professional labeling are conceptually the same, but are rewritten for 

understanding by the lay person.
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Knowledge Check
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Instruction: Knowledge Check

1. Read sample deficiencies

2. Find the missing part, one for each deficiency

3. Think about why adding the missing part is 

important
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Sample Deficiency #1

You did not identify fresh and frozen samples in the line 

data, nor did you stratify clinical performance by fresh 

and frozen status. To ensure we better understand the 

performance of your test under your proposed conditions 

of use identified in your draft labeling, please update the 

line data to indicate fresh and frozen status and stratify 

clinical performance by this parameter.
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Sample Deficiency #1

 What was provided (that is, the missed part)

 What is deficient

 Why it is needed

 What is needed
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Def. #1: added “What was provided”

You provided line data for your prospective study for your in vitro test. 

From the dates listed in the line data for specimen collection and 

inoculation, it appears that both fresh and frozen samples were tested.

However, you did not identify fresh and frozen samples in the line data, 

nor did you stratify clinical performance by fresh and frozen status. To 

ensure we better understand the performance of your test under your 

proposed conditions of use identified in your draft labeling, please 

update the line data to indicate fresh and frozen status and stratify 

clinical performance by this parameter.
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Sample Deficiency #2

You referenced the currently FDA-recognized version of ISO 7886-1 in your 

submission for your hypodermic syringe and did not include a declaration of 

conformity. You should demonstrate conformance to Clauses 6 and 7 (or 

demonstrate substantial equivalence (SE) otherwise) because your identified 

predicate device was determined to be SE through ISO 7886-1 conformance. 

Therefore, please provide the test results from these two tests or provide a 

declaration of conformity to the methods and acceptance criteria identified in 

Clauses 6 and 7 of ISO 7886-1, so that the FDA may assess whether your 

performance data support the SE of your device to the predicate device.
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Sample Deficiency #2

 What was provided

 What is deficient

 Why it is needed

 What is needed
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Def. #2: added “What is deficient”

You referenced the currently FDA-recognized version of ISO 7886-1 in your 

submission for your hypodermic syringe and did not include a declaration of 

conformity. While you have submitted several tests under ISO 7886-1, you did 

not include a summary of your testing regarding limits for acidity or alkalinity 

or limits for extractable metals (Clauses 6 and 7). You should demonstrate 

conformance to Clauses 6 and 7 (or demonstrate substantial equivalence (SE) 

otherwise) because your identified predicate device was determined to be SE 

through ISO 7886-1 conformance. Therefore, please provide the test results 

from these two tests or provide a declaration of conformity to the methods and 

acceptance criteria identified in Clauses 6 and 7 of ISO 7886-1, so that the FDA 

may assess whether your performance data support the SE of your device to the 

predicate device.
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Sample Deficiency #3

You have provided the protocols and results from a cytotoxicity test using your device in 

its final finished form, as recommended by the FDA guidance “Use of International 

Standard ISO 10993-1”. However, we have identified the following inadequacies in your 

testing: 

a. The currently FDA-recognized standard ISO 10993-12 recommends the use of 

surface area to determine the amount of device included in the extract. Please 

provide information to demonstrate that the use of weight to determine extraction 

ratio has an equivalent or greater amount of test article as compared to use of 

surface area.

b. (not included for brevity)

If you cannot provide an adequate rationale, the FDA recommends that you complete 

new cytotoxicity testing using a sample preparation approach consistent with the surface 

area recommendations in the currently FDA-recognized version of ISO 10993-12.
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Deficiency #3

 What was provided

 What is deficient

 Why it is needed

 What is needed
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Def. #3: added “Why it is needed”

You have provided the protocols and results from a cytotoxicity test using your device in its final finished form, as 

recommended by the FDA guidance “Use of International Standard ISO 10993-1”. However, we have identified the 

following inadequacies in your testing: 

a. The currently FDA-recognized standard ISO 10993-12 recommends the use of surface 

area to determine the amount of device included in the extract. We are concerned 

that use of weight instead of surface area may result in a false negative finding from 

the study (i.e., a negative finding may occur as a result of insufficient sample being 

present in the test system). Please provide information to demonstrate that the use 

of weight to determine extraction ratio has an equivalent or greater amount of test 

article as compared to use of surface area.

b. (not included for brevity)

If you cannot provide an adequate rationale, the FDA recommends that you complete new cytotoxicity testing using 

a sample preparation approach consistent with the surface area recommendations in the currently FDA-recognized 

version of ISO 10993-12.
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Summary

1. The FDA follows least burdensome principles and 

guidance

2. Writing clear deficiencies helps improve understanding 

and resolution of regulatory issues

3. A well-written deficiency consists of four parts

4. Including all four parts allows complete understanding 

of issue and expectations
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For More Information

• FDA Third Party Review Program

www.fda.gov/medical-devices/premarket-submissions/third-party-review

• Contact the FDA Third Party Team

3P510k@fda.hhs.gov
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Your Call To Action

1. Fully understand the regulatory issues and 

details of submission

2. Apply the principles presented in this and the 

companion module when writing deficiencies 

and corresponding with sponsors