Table 8

Studies providing indirect adverse event definition & classification system (n = 15).

Authors, year, citationStudy designDefinitionClassification system
Senstad et al. 1996b []SurveyBenign and short-lasting discomfort“The patient was asked for the degree of pain (four choices ranging from “minor” to “unbearable”). The chiropractor then asked three questions: 1) “How soon after the treatment did the reaction start?”, 2) “How long did the reaction last?”, and 3) “Could you carry out your usual work?” ’’
Ernst et al. 2001 []Review“Transient exacerbation of symptoms’’;Light, moderate, fairly severe and more than that’’; ’’Serious injury’’; ’’Mild, moderate, definitely unpleasant, and unbearable’’; ’’The onset of symptoms was mostly on the day of the intervention. or the day after’’; ’’Moderate, slight’’; ’’Very noticeable. . . . associated with a reduction in the ability to work’’; ’’. . . .had disappeared within 24 hours’’
’’Unpleasant reactions’’;
’’Adverse response, no matter how minor or fleeting’’;
’’Any discomfort (other than presenting symptoms) experienced after treatment’’
Cagnie et al. 2004 []Survey Unpleasant reactions “The patient was asked to report the type of reaction, time of onset, duration and severity of symptoms, whether any reaction had caused difficulty in performing daily activities and how they felt 48hr after treatment’’
Murphy et al. 2006 []Case Reports/Series“Transient increase in pain to serious complications’’Major complications; transient adverse reactions; short-lived, transient
Bronfort et al. 2008 []ReviewBenign temporary side effects; typically does not interfere with activities of daily livingTypically does not interfere with activities of daily living; occurred within 4 hours; mild-to-moderate severity; disappeared the same day
Brantingham et al. 2009 []TrialSerious adverse reactions (e.g., defined as persistent severe knee stiffness, swelling and/or pain)’’ Mild, serious
Langworthy et al. 2010 []Survey"Serious adverse reaction to cervical spine manipulation resulting in stroke or other significant neurological damage" Serious
Bronfort et al. 2012 []TrialExpected, typical of treatment; transient in nature, requiring little or no change to activity levels Serious / nonserious
Rajendran et al. 2012 []Qualitative StudyLoss of function, particularly if it had an impact on work or daily activities; unexpected, in nature or intensity; unacceptableMajor, moderate, or minor and “not adverse’’, were classified according to duration, severity and seriousness/acceptability
Page et al. 2014 []ReviewPain persisting longer than 2 hours after treatment or more disability the next morning Mild, minor, serious
Bronfort et al. 2014 []TrialDifferent type of pain; Mild, moderate, self-limiting, serious
Increased symptom severity;
Increased difficulty with activities
Bussieres et al. 2018 []Clinical Practice GuidelineUndesirable effects/outcome; transient increase in painUndesirable; serious
Morris et al. 2018 []Observational StudyInjury or loss of normal function; increased pain or new pain complaints. Therapeutic measures were/were not required“All complications were classified as an ‘unexpected pain exacerbation’ ’’
Peters et al. 2019 []Observational StudyNon-serious adverse events“Intensity and duration linked to the following: (1) aggravation of complaints in treated area; (2) radiating pain to an upper extremity; (3) headache; 4) stiffness in the treated area; (5) tiredness; (6) dizziness or light-headedness; (7) nausea; 8) ringing in the ears; (9) confusion or disorientation; (10) cramps; (11) blurred vision; (12) weakness in the limbs; (13) vomiting; and (14) any other symptom not defined by any of the previous categories’’
Mabry et al. 2020 []Observational StudyEvents that have reached a patient and are subsequently categorized by the level of harm endured by the patientMild, transient, and self-limiting adverse events’’