Supporting Statement Part B_ CDI supporting statement_Ext_FL

Clostridium difficile Infection (CDI) Surveillance– Part B

Extension without Change

Approval Number: 0920-0892

December 12, 2013

Contact:

Fernanda Lessa, MD, MPH

Medical Epidemiologist

Surveillance Branch

Division of Healthcare Quality Promotion

Centers for Disease Control and Prevention

1600 Clifton Rd NE, MS A-24

Atlanta, GA 30333

Phone: 404-639-7798

Fax: 404-639-2647

[email protected]

Table of Contents for Part B:

1. Respondent Universe and Sampling Methods Pages 3-5

2. Procedures for the Collection of Information Pages 5-7

3. Methods to Maximize Response Rates and Deal with No Response Page 7

4. Tests of Procedures or Methods to be Undertaken Page 7-8

5. Individuals Consulted on Statistical Aspects and Individuals

Collecting and/or Analyzing Data Page 8

Part B. Collections of Information Employing Statistical Methods

1. Respondent Universe and Sampling Methods

Cases will be identified by laboratory surveillance for toxin-positive C. difficile specimens from clinical laboratories in the CDI EIP surveillance area. The number of study participants to be enrolled will be dependent on the number of positive, non-recurrent and non-duplicate specimens received and meeting other inclusion criteria. All patients over the age of one year and of any health status will be eligible.

The total population of CDI surveillance is approximately 11.4 million persons. The table below illustrates the population under surveillance for each EIP site as of January 2013.

State	Surveillance sites	Estimated CDI Surveillance Population
CA	San Francisco County	812,826
CO	Adams, Arapahoe, Denver, Douglas, Jefferson Counties	2,488,410
CT	New Haven County	861,113
GA	Clayton, Cobb, DeKalb, Douglas, Fulton, Gwinnett, Newton and Rockdale Counties	3,753,452
MD	Washington, Frederick, Cecil, Kent, Queen Anne’s, Caroline, Talbot, Dorchester, Somerset, Wicomico, Worcester Counties	835,893
MN	Stearns, Todd, Benton, Morrison, Olmstead Counties	393,848
NM	Bernalillo County	812,826
NY	Monroe County	745,625
OR	Klamath and Deschutes County	226,637
TN	Davidson County	635,475
TOTAL	---------	11,424,247

*Populations were retrieved from the US Census Bureau 2011 national estimates

Crude population estimates for community- and healthcare facility-onset CDI were obtained based on 2011 EIP C. difficile surveillance data. These estimates were used to calculate workload volumes and disease burden.

	Estimated incidence per year (per 100,000)	Estimated number of cases reported to EIP program per year
All toxin positives	170	19,421
Contribution of duplicate episodes	10	1,142
Contribution of recurrent episodes and out-of-catchment specimens	20	2,284
Incident cases	140	15,993
HCFO	68	7,768
CO	72	8,225
CO-HFCA	27	3,084
CA	45	5,140

CDI cases will be identified using positive C. difficile toxin assay data from all healthcare facility-based clinical laboratories as well as outpatient diagnostic clinical laboratories serving the population under surveillance. Each clinical laboratory in the surveillance area will regularly provide laboratory line listings of all positive C. difficile test results to the local EIP sites. Information on additional positive specimens from the same patient will be recorded for the purpose of ascertaining and tracking recurrent or duplicate episodes, as well as, new incident cases (i.e. greater than eight weeks after the last positive C. difficile specimen). Case report forms will not be completed on recurrent or duplicate episodes, and for patients determined to reside outside catchment area or who are < 1 year of age. Distinction between infection and colonization in persons aged < 1 year of age has not been well described in the literature.

Application of sampling at selected EIP sites. Two sites, Colorado and Georgia, which make up approximately 50% of the total population of the CDI surveillance area, anticipate relatively high volume of positive C. difficile toxin specimens. These sites will apply a stratified random sampling strategy after determining which specimens qualify as incident C. difficile stool specimens (i.e. specimens from the same patient greater than 8 weeks after the last positive specimen) in a surveillance are resident 1 year of age or older. Sampling will be stratified by age group and gender. All pediatric cases (i.e., 1-17 years of age) will be selected for full medical record review, while only 33% of the cases in the other strata will have full medical record review performed.

Application of sampling of HCFO cases at all EIP sites. Among CDI cases classified as HCFO, 1 in 10 will be randomly selected for case report form completion. Since the epidemiology of HCFO cases has been described elsewhere^4,5, these cases will be sampled in order to reduce the burden of data collection. In contrast, a case report form will be completed on all CO-CDI cases. From these data, CO-CDI cases will be classified as either CO-HCFA or putative CA-CDI cases.

2. Procedures for the Collection of Information

EIP site surveillance officers are employees of the State Health Department or state

agents. They will collect from clinical laboratories in the surveillance area, on a weekly

or monthly basis, a line list of positive C. difficile toxin assay test results and patient

identifying information. Each positive assay result will be cross-checked with a dataset

containing previous line lists of positive C. difficile toxin tests to determine if episodes

are duplicate, recurrent or incident CDI case. The addresses of possible incident CDI

case-patients will be reviewed to determine if they reside within the surveillance

catchment area. Those patients residing outside of the catchment area will be excluded

from further investigation but captured as a count in a separate database if individual sites

need to track this information. CDC will not receive any information on individuals who

reside outside of surveillance catchment area.

All CDI cases identified will be evaluated by EIP personnel for initial case classification

using data from the laboratory line list. Secondary case classification will be performed

using electronic health data and/or chart review. A detailed review of the medical record

will be necessary to complete the full case report form on case-patients. Demographic

data, clinical features, key exposure variables, co-morbidities and outcomes will be

collected (Appendix E). A case report form will be completed by trained surveillance

staff for selected HCFO CDI cases and for all CO CDI cases.

CDI cases classified as putative community-associated CDI (CA-CDI) will undergo a

health interview to collect supplemental information on healthcare, medication, food, and

environmental exposures that might not be captured in the medical records (Appendix F).

Health interviews will be conducted by trained staff at EIP sites in either English or

Spanish. At sites where it is required, an infection control specialist will call patients to

get their permission to be contacted for an interview by the EIP staff (Appendix G). EIP

staff will make 10 attempts to reach eligible CA-CDI case-patients. These 10 attempts

will include no answer and leaving a message. No further attempts will be made if

patients indicate that they not wish to participate in the health interview. Prisoners will

not be eligible for health interview.

For some states, where it is required by their local IRBs, the primary physician will be

notified by letter (Appendix H) that EIP personnel will be contacting the case-patient

about their recent C. difficile infection. At states where it is required, physician

notification and paper consent form will be sent to the putative CA-CDI case-patient

prior to conducting a health interview.

For states where C.difficile is reportable, the Privacy Rule allows for covered entities to

disclose protected health information to public authorities (including the states) without

individual authorization under the provisions for public health practice. In the states

where the illness is reportable, state public health statutes allow for the contact of

individuals to gather information to protect public’s health.

For states where C. difficile is not reportable, the Privacy Rule allows covered entities to

disclose protected health information without individual authorization when criteria for a

waiver are met. According to Federal regulations for the protection of human subjects in

research under 45 CFR 46.109 and 46.111, IRBs reviewing proposed research protocol

have the authority to allow researchers to contact individuals to invite them to participate

in research.

3. Methods to Maximize Response Rates and Deal with Nonresponse

This surveillance project is being conducted through the EIP infrastructure in which each

of the 10 sites has established relationships with laboratories and healthcare facilities

within their defined catchment areas. Personnel at these sites have regular contact with

the facilities and encourage all facilities and laboratories to participate. Audits of the

clinical laboratories in the surveillance area will be performed 1-2 times per year by local

EIP personnel to ensure complete ascertainment of cases. HIPAA regulation allows for

the disclosure and use of protected health information for research purposes without

individual authorization because criteria for a waiver were met. CDC personnel will not

perform these audits. Completeness and correctness of data collected should be assessed

and cross-checked regularly to identify and address issues with the data collection or the

application of surveillance definitions to ensure response. CDC staff will perform site

visits to the EIP sites on a yearly basis to evaluate compliance with standard operational

procedures.

4. Tests of Procedures or Methods to be Undertaken

To understand the logistics and resources required to initiate and maintain a longitudinal,

multi-site CDI surveillance program, a pilot surveillance study was conducted through

CDC’s Foodborne Diseases Active Surveillance Network (FoodNet). This pilot study

aimed to identify strengths and challenges to conducting CDI surveillance in three

hospitals located at two EIP sites (New York and Connecticut) over a three month period.

The methodology, case report form, and health interview questionnaire described above

take into account the findings from this pilot project⁷.

5. Individuals Consulted on Statistical Aspects and Individuals Collecting and/or

Analyzing Data

Contact information for the statistician consulted for project design and data analysis is as follows:

Jonathan R. Edwards, MStat

Leader, Statistics Team

Surveillance Branch, Division of Healthcare Quality Promotion

Centers for Disease Control and Prevention

1600 Clifton Rd, NE

Atlanta, GA 30333

(404) 639-4177

Email: [email protected]

Data will be collected by EIP personnel and by local facility staff, as described previously. Identification of the specific EIP surveillance officers and local facility staff members who will participate in training and data collection activities is at the discretion of the EIP site or the facility, respectively.

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