Table 1.
Baseline characteristics of the included studies
| Author (year) | Country | CA-CDI definition | Samples processed | Diagnostic tool | Age group | Population | CA-CDI cases | Timeframe in years |
|---|---|---|---|---|---|---|---|---|
| Kotila, et al. (2016) | Finland | Infection obtained outside a hospital, >4 weeks after hospital discharge, or < 2 days after admission | NR | TcdA, TcdB, culture of C. difficile, and NAATs | Mixed | 5,500,000 | 10,643 | 6 |
| Penit, et al. (2016) | France | Symptoms starting 8 weeks after hospital discharge or in the first 48 h of hospital stay | NR | ELISA, C-Dff Quik Chek Complete, C. difficile glutamate dehydrogenase, and toxin A/B antigens | Mixed | NR | 27 | 0.58 |
| Banks, et al. (2015) | Scotland | CDI case with onset of symptoms while outside a healthcare facility, and without discharge from a healthcare facility within the previous 12 weeks or with onset of symptoms within 48 h following admission to a healthcare facility without residence in a healthcare facility within the previous 12 weeks | NR | NR | >15 years old | 1,601,849 | 158 | 1 |
| Khanna, et al. (2016) | USA | Symptom onset occurred in the community or within 48 h of admission to a hospital, provided symptom onset was more than 12 weeks after the last discharge from a hospital. | NR | NR | Adults | 308,745,538 | 263 | 8 |
| Mori, et al. (2015) | Japan | Patient presenting in the outpatients setting with a diagnosis of CDI with no history of hospital discharge in the 12 weeks prior to the visit | 208 | C. difficile toxin assay or C Diff Quick Chek complete, isolates of C. difficile on stool culture and Immunocard CD toxin A & B | Adults and elderly | 1,914,011 | 26 | 5 |
| Alcalá, et al. (2015) | Spain | Patient with onset of symptoms while outside a healthcare facility, and without discharge from a healthcare facility within the previous 12 weeks or with onset of symptoms within 48 h following admission to a healthcare facility without residence in a healthcare facility within the previous 12 weeks | 1800 | CLO agar culture | Mixed | 31,140,726 | 40 | 0.58 |
| Jamal, et al. (2015) | Kuwait | Onset of symptoms occurring while the patient was outside a healthcare facility and the patient had not been discharged from a healthcare facility within 12 weeks before symptom onset, or the onset of symptoms occurring within 48 h upon admission to a healthcare facility and the patient had no prior stay in a healthcare facility within the 12 weeks prior to symptom onset | 2,584 | Presence of typical fluorescence color under UV light and API 20AN | Mixed | 3,268,431 | 16 | 2 |
| Lessa, et al. (2014) | USA | Positive C difficile specimen was collected as an outpatient or within 3 days after hospital admission and the patient had no documented overnight stays in a healthcare facility in the prior 12 weeks | NR | NAAT | Mixed | 308,745,538 | 3,207 | 1 |
| Taori, et al. (2014) | Scotland | CDI, which developed in a patient with no history of healthcare contact in the 12 weeks prior to diagnosis | NR | Toxin A and/or B by EIA and glutamate dehydrogenase, toxin A, and toxin B PCR17 | Mixed | 664,760 | 42 | 1 |
| Slimings, et al. (2014) | Australia | Symptom onset in the community or < 48 h after admission to a hospital if symptom onset occurred >12 weeks after last discharge from a hospital | NR | Laboratory assay for C. difficile toxin A and/or B, or stool sample by culture or PCR. | Mixed | NR | 1,320 | 2 |
| Ingle, et al. (2013) | India | No history of past or present hospitalization in the past 12 weeks | 150 | C. difficile toxin (CDT) assay microscopy and culture, CDT A and B with ELISA | Mixed | NR | 2 | 1.75 |
| Gutiérrez, et al. (2013) | USA | Community acquired CDAD cases were individuals without in patient medical encounters in the twelve-week period prior to CDAD diagnosis | NR | NR | Adults | NR | 1,018 | 13 |
| Khanna, et al. (2012) | USA | Onset of symptoms occurred in the community or within 48 h of admission to a hospital, provided symptom onset was >12 weeks after the last discharge from a hospital | NR | NR | Mixed | 123,310 | 157 | 15 |
| Mitchell, et al. (2012) | Australia | Symptom onset was in the community or within 48 h of admission to a public hospital provided that symptom onset was more than 12 weeks after the last discharge from a healthcare facility in which skilled nursing care is provided, excluding residential aged care | NR | enzyme immunoassay or polymerase chain reaction detecting toxin A and/or toxin B, or culture | Mixed | NR | 17 (in 2010) 54 (in 2011) |
1 |
| Vesteinsdottir, et al. (2012) | Iceland | If patients had not been hospitalized for the past 6 weeks, did not live in a nursing facility such as a nursing home or retirement home, and, if hospitalized, were diagnosed with CDI within 72 h from admission | 1,693 | CD toxin A and B by ELISA | Adults and elderly | 318,452 | 30 | 1 |
| Kuntz, et al. (2011) | USA | Diagnosis of CDI in the outpatient setting with no history of hospital discharge in the 12 weeks before diagnosis, or (2) a primary diagnosis upon hospital admission and no history of hospital discharge in the 12 weeks before diagnosis | NR | Primary or secondary diagnosis of ICD–9 code 008.45 for ‘Infection due to Clostridium difficile’ listed on an inpatient or outpatient insurance claim | Mixed | 680,783 | 304 | 4 |
| Allard, et al. (2011) | Canada | NR | NR | Mixed | 1,850,000 | 536 | 1 | |
| Kutty, et al. A. (2010) | USA | Patients for which there was no inpatient healthcare exposure within 8 weeks before the stool collection date | NR | C. difficile Tox A/B II ELISA | Veterans Affairs and Adults and elderly | NR | 212 | 1 |
| Norén, et al. (2004) | Sweden | Patients with community-acquired CDAD had no history of recent hospitalization | 2,115 | Antitoxin antibody neutralization, culture on cycloserine- cefoxitin-fructose agar | Mixed | 274,000 | 59 | 1 |
| Karlström, et al. (1998) | Sweden | Onset of symptoms outside the hospital without hospitalization within the preceding 4 weeks | NR | Culture (cycloserine-cefoxitin-fructose agar) and toxin A/B assay by immunologic | Mixed | 8,800,000 | 89 | 1 |
| van Dorp, et al. (2019) | Netherlands | 12,714 | NR | Mixed | 2,810,830 | 124 | 1.33 | |
| Xia, et al. (2019) | Canada | CDI case with symptom onset in the community OR occurring less than or equal to 72 h or less than or equal to three calendar days after admission to a healthcare facility, provided that symptom onset was more than four weeks after the patient was discharged from any healthcare facility | NR | NR | NR | 14,362,183 | 10,099 | 6 |
| Lefevre-Tantet-Etchebarne, et al. (2016) | France | Acquired >12 weeks from hospitalization | 2055 | Glutamate dehydrogenase analysis by immunochromatographic test, and toxin analysis by immunochromatographic test and toxin-secreting strain culture | Adults and elderly | NR | 28 | 3 |
| Zilberberg, et al. (2016) | USA | If there was no evidence of an acute, nursing home, or skilled nursing facility stay within 12 weeks before the incident CDI episode or if there was no ICD–9-CM code for CDI | NR | NR | Elderly | 1,165,165 | 1,197 | 2 |
| Reigadas, et al. (2014) | Spain | Onset of symptoms while outside a healthcare facility, and without discharge from a healthcare facility within the previous 12 weeks or with onset of symptoms within 48 h following admission to a healthcare facility without residence in a healthcare facility within the previous 12 weeks | 1,270 | Toxigenic culture in Clostridium selective agar medium, immunochromatographic system and the MRC–5 cell line cytotoxicity test. | Mixed | NR | 38 | 0.5 |
| Marwick, et al. (2013) | Scotland | Onset of symptoms while outside a healthcare facility, and without discharge from a healthcare facility within the previous 12 weeks OR onset of symptoms within 48 h following admission to a healthcare facility, and without residence in a healthcare facility within the previous 12 weeks | NR | Toxin A & B test and/or the C. DIFF QUIK CHEK COMPLETETM test | Elderly | 79,039 | 137 | 1 |
| Hirschhorn, et al. (1994) | USA | Onset at least 42 days after the most recent hospitalization, CDAD with onset within 48 h of admission or CDAD in a patient admitted to a hospital with gastrointestinal symptoms and a positive assay for C difficile toxin within 5 days of admission | 668 | Cytotoxic assay as the confirmatory test for samples by latex agglutination. | Mixed | 265,000 | 51 | 3 |
| Asensio, et al. (2021) | Spain | Infections on patients with more than 4 weeks of discharge from a healthcare facility or with unknown origin | NR | Toxin A and B determination, PCR | Mixed | 465,620 | 430 | 8 |
| Zanichelli, et al. (2020) | Canada | Illness in a hospitalized patient for whom symptoms developed within 72 h of admission and who had not been hospitalized or received ambulatory care in the previous 4 weeks. | NR | Nucleic acid amplification tests and enzyme immunoassays for detecting toxigenic C. difficile | Mixed | 8,209,599 | 4,481 | 7 |
| Maisa, et al. (2019) | Ireland | No history of hospital admission >4 weeks from hospitalization; including cases with a positive CDI result 4–12 weeks of hospitalization OR < 48 h following hospital admission and no previous hospital stay within 4 weeks | 2,807 | Either glutamate dehydrogenase enzyme immunoassay or PCR testing, followed by toxin detection using ELISA | Mixed | 1,866,042 | 1,303 | 5 |
| Ho, et al. (2017) | China | Patients who had not been hospitalized in a healthcare facility within the previous 12 weeks | NR | Bacterial culture, toxin detection, NAAT | Adults and elderly | 6,085,892 | 817 | 9 |
| Abrahamian, et al. (2017) | USA | All cases that did not occur in participants with an overnight hospital or nursing home stay in the previous 3 months | 422 | C. difficile-positive culture result and positive toxin assay result either by the GeneXpert or ELISA | Mixed | NR | 17 | 2.5 |
| Kumar, et al. (2018) | Bailiwick of Jersey | Infection onset in the community with no prior admission to a healthcare facility for at least 84 days (12 weeks) | 4,506 | CD toxin enzyme immunoassay, glutamate dehydrogenase EIA | Mixed | 99,000 | 29 | 5 |
| Malmqvist, et al. (2019) | Sweden | Onset outside of healthcare facility and > 12 weeks since hospital discharge or onset within 48 h after admission to healthcare facility and > 12 weeks since hospital discharge | 3,377 | cell cytotoxicity assay using human embryonic lung fibroblasts, cytotoxicity neutralization assay for Toxin B and nucleic acid amplification test | Children | 426,724 | 46 | 8 |
| Russo, et al. (2019) | USA | Onset occurred in the community (outpatient setting) with no history of hospitalization, or long-term care, or skilled nursing facility stay during the previous 12 weeks | NR | Diagnosis code for CDI (ICD–9-CM 008.45 or ICD–10 A04.7 or the presence of toxin or toxin gene in a stool sample detected by enzyme immunoassay or polymerase chain reaction (PCR). | Adults | 1,073,900 | 5,066 | 6 |
| Weil, et al. (2007) | Germany | NR | 703 | enzyme immunoassay for C. difficile toxin A/B and culture | Mixed | NR | 35 | 0.5 |
| Furuya-Kanamori, et al. (2014) | Australia | Patient from the community that submitted a positive specimen for C. difficile toxin gene detection | 24,496 | tcdE and assay was agarose gel based or real time PCR with dual targets tcdE and tcdB | Mixed | 4,500,000 | 1792 | 10 |
| Yu, et al. (2022) | USA | Cases identified from the outpatient setting or an inpatient facility ≤3 days after admission, with no inpatient stay in the previous 12 weeks | NR | laboratory CDI test cell culture cytotoxicity assay, immunoassay, nucleic acid amplification | Elderly | 6,100,000 | 61,470 | 8 |
| Collins, et al. (2022) | Australia | NR | 381 | PCR result for tcdB, enzyme immunoassay for glutamate dehydrogenase (GDH), tcdB PCR | NR | 2,200,000 | 112 | 3 |
| Azimirad, et al. (2020) | Iran | Patients that developed CDI symptoms in the community or within 48 h or less after hospital admission. These patients must not have been discharged from a health-care facility in the previous 12 weeks | 3,649 | Cultured on cycloserine-cefoxitin-fructose agar, PCR on 16S rDNA gene | Mixed | NR | 292 | 15 |
| Younas, et al. (2019) | USA | Positive stool specimen was collected in an ambulatory setting or within three calendar days of hospital admission in a person with no documented overnight stay in a healthcare facility during the 12 weeks before the specimen was collected | NR | Nucleic-acid amplification test (NAAT), glutamate dehydrogenase test and enzyme immunoassays for toxin detection | Mixed | NR | 5,192 | 1.5 |
| Dantes, et al. (2015) | USA | Cases with no positive test ≤8 weeks prior and no overnight stay in a healthcare facility ≤12 weeks prior | NR | NAAT | Adults and elderly | 10,400,000 | 4,682 | 1 |
| Johnston, et al. (2021) | New Zealand | Cases with >12 weeks after discharge | 1,153 | Initial glutamate dehydrogenase screening assay, toxin enzyme immunoassay test | Mixed | NR | 9 | 1 |
| Guh, et al. (2020) | USA | Cases with no documented admission to a health care facility in the preceding 12 weeks | NR | NAAT | Mixed | 12,000,000 | 47,512 | 7 |
| Miranda, et al. (2020) | USA | Cases evaluated in the community or first 48 h of hospital admission and > 12 weeks after hospital discharge, with no prior positive C difficile testing in last 8 weeks, without other identified causes of diarrhea | 7,650 | Glutamate dehydrogenase antigen, PCR | Children | 3,642,281 | 554 | 5 |
| Bodé, et al. (2018) | Spain | Patient with CDI symptom onset in the community or 48 h or less after admission to a health care facility, provided that symptom onset was more than 12 weeks after the last discharge from an health care facility | 7,004 | Toxigenic culture on selective cycloserine cefoxitine fructose agar plates, Glutamate-dehydrogenase rapid enzyme immunoassay screening test was performed, rapid dual enzyme immunoassay screening test | Mixed | NR | 151 | 2 |
| Lasheras, et al. (2018) | Spain | Case of CDI with onset of symptoms: outside of healthcare facilities AND without discharge from a healthcare facility within the previous 12 weeks, or on the day of admission to a healthcare facility or on the following day and not resident in a healthcare facility within the previous 12 weeks | 137 | Toxigenic culture and enzyme immunoassay | Mixed | 200,000 | 4 | 0.41 |
| Na’amnih, et al. (2017) | Israel | Symptom onset in the community or within 48 h of admission to a hospital without any hospitalization in the previous 12 weeks and a positive stool sample within 48 h of admission | 1,563 | Enzyme immunoassay to detect toxin A/B, GDH and Toxin A/B immunochromatographic rapid test, CDT PCR | Adults and elderly | 2,367,540 | 84 | 8 |
| Garabasova, et al. (2017) | Slovakia | NR | NR | Epidemiological data, clinical picture (basic clinical symptoms and signs), microbiological tests (positive laboratory assay for C. difficile toxin A and/or B in stools) | Mixed | NR | 51 | 0.25 |
NR: Not reported; CA-CDI: Community acquired Clostridioides difficile infection.