Acute procedure anxiety in adults: Epidemiology, clinical manifestations, and course

INTRODUCTION — Acute procedure anxiety is an excessive fear of medical, dental, or surgical procedures that results in acute distress or interference with completing necessary procedures. Patients may experience anxiety in anticipation of and/or during many types of procedures, including for screening (eg, mammography), diagnosis (eg, amniocentesis or endoscopy), and treatment (eg, angioplasty or open heart surgery).

Specific phobias are a subset of the varied manifestations of acute procedure anxiety, diagnosed under DSM-5 criteria only when the patient’s fears are specific to a procedure and its immediate effects (eg, fear of suffocation during magnetic resonance imaging [MRI]) rather than fears not specific to the procedure itself (eg, a fear of the underlying illness that might be diagnosed). Specific phobias related to clinical procedures include blood-injection-injury phobia, dental phobia, and MRI claustrophobia.

This topic addresses the epidemiology, clinical manifestations, and course of acute procedure anxiety in adults that is related to common medical and surgical procedures. The topic includes specific phobias where the fear/anxiety is related to clinical care. Specific phobias unrelated to clinical care are discussed separately. The screening, assessment, diagnosis, and treatment of acute procedure anxiety are also discussed separately. (See "Acute procedure anxiety in adults: Course, screening, assessment, and differential diagnosis" and "Treatment of acute procedural anxiety in adults" and "Specific phobia in adults: Epidemiology, clinical manifestations, course and diagnosis" and "Cognitive-behavioral therapies for specific phobia in adults" and "Pharmacotherapy for specific phobia in adults".)

OVERVIEW AND TERMINOLOGY

Acute procedure anxiety — Acute procedure anxiety, which is not a diagnosis found in DSM-5 [1], is an excessive fear and/or anxiety about a medical procedure that results in acute distress in anticipation of the procedure or during the procedure, or avoidance of the procedure. The fears may be rational (eg, concern that a breast biopsy may find a malignancy) or irrational (eg, fear of suffocation during magnetic resonance imaging [MRI]).

Specific phobias — Presentations of acute procedure anxiety are diagnosed as a specific phobia under DSM-5 criteria only when the focus of patients’ fear is specific to the procedure or its immediate effects (eg, a fear of seeing blood during venipuncture or suffocating during an MRI scan). A specific phobia would not be diagnosed when the patient’s fear/anxiety is about, for example, the implications or outcomes of the procedure (eg, the fear that a diagnostic procedure may detect an illness with a poor prognosis). Specific phobias related to clinical procedures include blood injection injury phobia, dental phobia, and MRI claustrophobia.

Blood-injection-injury phobia — Blood-injection-injury phobia is characterized by the fear of seeing blood, receiving an injection, or of other invasive medical procedures [2]. Blood-injection-injury phobia is distinguished from other subtypes of specific phobia by the presence of a vasovagal fainting response, which occurs in the majority of individuals diagnosed with the subtype [3]. The fainting response in specific phobia appears to be unique to situations associated with blood and medical procedures. Disgust sensitivity may be a possible mediator of the fainting response [4].

Dental phobia — Dental phobia is the specific fear of going to the dentist, and the fear may be triggered by multiple stimuli in the dental office, such as sound of the drill, receiving an intraoral injection, or undergoing any dental treatment.

MRI claustrophobia — Claustrophobia is the specific fear of enclosed spaces and is categorized under the situational subtype of specific phobia in DSM-5 small spaces because patients in MRI scanners are required to be in a very tight space without moving and remain in an uncomfortable position for an extended period of time. There is significant noise interference, and the room temperature in an MRI suite is often cold.

EPIDEMIOLOGY — Given the large number of diagnostic, medical, and surgical procedures in contemporary health care, there is surprisingly scant literature on rates of procedure-related anxiety. Large community based epidemiology studies that used structured interviews to estimate the lifetime prevalence of acute procedure anxiety are limited to specific phobias of blood-injection-injury phobia and dental phobia [5-7].

Studies reporting the prevalence rates of magnetic resonance imaging (MRI) claustrophobia and acute procedure anxiety in patients undergoing specific medical or surgical procedures unrelated to a diagnosis of specific phobia are all cross-sectional studies that measure the level of anxiety at the time of the study.  

Many of these studies have methodologic limitations, including the use of self-assessment questionnaires that vary widely, from one-item visual analog scales to instruments with established reliability and validity.

Specific phobias — Community-based studies have estimated that 2 to 5 percent of the general population in the United States has experienced blood-injection-injury phobia or dental phobia.

Blood-injection-injury phobia — Community-based epidemiologic studies using semi-structured diagnostic interviews estimated that 3.1 to 4.5 percent of the general population in the United States suffers from blood-injection-injury in their lifetime [5-7]. All of these studies included dental phobia within the blood-injection-injury phobia subtype. Within this subtype, one study found that 23 percent had a fear of blood, 47 percent a fear of injections, and 78 percent a fear of dentists [7].

●Clinical setting – In medical settings, the point prevalence of fear of blood or injection phobia ranges from 7 to 9 percent:

•A study of 3315 adults undergoing venipuncture in a United States outpatient hospital-based phlebotomy clinic reported that 7.5 percent of the participants reported significant anxiety symptoms during the procedure [8]. Patients experiencing anxiety were more likely to report a history of vasovagal reactions and vasovagal syncope compared with patients who did not, and were also more likely to report significant fears of fainting, disgust, pain, and health concerns during injections. The study had multiple limitations, including the absence of a standardized instrument to assess anxiety.

•In a study of 1275 patients with insulin-dependent type I or II diabetes in the Netherlands, 9.3 percent endorsed extreme fear of injecting themselves with insulin and testing their glucose levels [9].

•Among 1529 pregnant women attending an antenatal clinic in Sweden, an estimated 7.2 percent met DSM-IV diagnostic criteria for blood-injection-injury phobia [10].

●Community – A community-based study of 1920 individuals found that blood-injection-injury was more common in females, younger adults, and adults with less education compared with individuals in the general population [7].

Dental phobia — An estimated 2.4 percent of the general adult population in the United States in their lifetime meets criteria for DSM-IV-TR dental phobia, based on semi-structured diagnostic interviews in a sample of 43,093 adults [6]. The point prevalence of anxiety over dental procedures has been estimated at 10 percent, based on studies that have used self-report screening questionnaires [11].

The point prevalence of dental anxiety in the United States have been found to vary across population subgroups, with rates of 14 percent in adults over 65 [12], 19 percent in university students [13], and as high as 37.8 percent among HIV-positive patients [14]. Similar rates have been found internationally; as an example, in a university dental practice in Turkey, 13.4 percent of dental patients reported high levels of dental anxiety [15].

A higher prevalence of dental anxiety, compared with dental phobia, is expected, as a phobia diagnosis requires additional functional impairment or distress criteria. In a study of 18-year-olds in New Zealand, only 8 of 100 individuals who screened positive for dental anxiety met DSM-III-R criteria for dental phobia [16].

Dental anxiety tends to occur more commonly in females [11,12,14,15] and those with less education [11,12]. Dental anxiety is also more common in patients in the lower income bracket, those without dental insurance, and those without a usual place for dental care [11]. Studies have reported mixed results regarding the influence of age and race [11,12,17].

MRI claustrophobia — The point prevalence of MRI claustrophobia has been estimated at 1.8 to 2.3 percent:

●In a 2007 cohort study of 55,734 patients referred for an MRI examination using a conventional magnetic resonance scanner or a newer scanner with a wider magnetic bore, a total of 1.8 percent of patients were noted to have claustrophobia [18]. Claustrophobia was determined to be present if the patient had an anxious or panic reaction that resulted in premature termination of scanning or required medication to complete the scan [18].

The rate of MRI claustrophobia in the general population may be higher than that estimated in the study, as claustrophobia was stringently defined as requiring sedation or premature termination of scanning during an actual MRI examination. Patients who have claustrophobia would not have been included as a case of claustrophobia if they did not take medication but completed the MRI examination despite great distress.

●A review of previous MRI studies with conventional magnetic resonance scanners from 1984 to 2004 with a total of 17,961 patients reported an estimated rate of claustrophobia to be 2.3 percent [18]. Claustrophobic reactions are less likely to occur in the newer scanners with a wider magnetic bore compared with convention MRI machines (0.7 versus 2.1 percent) [18]. MRI claustrophobia is more likely to occur in females, those in middle age (40 to 65 years of age), and during head-first examinations [18].

As an example, in a study of 1215 women with elevated risk of breast cancer who participated in a trial of supplemental MRI screening for the disease, 42.1 percent of participants declined further screening with breast MRI [19]. Of those who declined, 25.4 percent of them refused because of claustrophobia.

A relatively high rate of unexpected claustrophobic reactions during MRI scanning [20] suggests the possibility that patients can be anxious in an MRI scanner without having pre-existing claustrophobic reactions to other small spaces.

Screening procedures — Of patients undergoing screening procedures, 15 to 38 percent reported significant levels of anxiety at the time of the study (point prevalence):

●Transvaginal ultrasonography – A study of 145 women in the United States who had an elevated risk of ovarian cancer and were screened for the disease with transvaginal ultrasonography found that 38 percent of premenopausal women and 27 percent of postmenopausal women experienced high levels of cancer risk-related anxiety prior to their first screening test [21].

●Colonoscopy – The rate of preprocedural anxiety among patients undergoing colonoscopy has been reported to range from 33 percent in the United States [22] to 36 percent in Taiwan, with 10 percent endorsing moderate to severe anxiety in Taiwan [23]. A high level of preprocedural anxiety was associated with increased pain and discomfort after the procedure [22].

A study of 45 patients undergoing a screening colonoscopy because of a strong family history of colorectal cancer found that 65 percent reported moderate anxiety and 19 percent reported severe anxiety prior to the procedure [24]. Acute procedure anxiety during colonoscopy has been reported as tending to occur more commonly among women and patients younger than age 40 [25].

●Mammography – The rate of anxiety among women undergoing a routine mammography is relatively low. A study of 4249 patients undergoing routine mammography in Norway found 15 percent of patients screened positive for anxiety [26]. A smaller study of 56 mammography patients reported that the presence of anxiety is associated with lower educational levels and first time experience with mammography [27].

●Other screening procedures – Moderate mean levels of acute anxiety were found in an observational study of 522 women undergoing gynecological exams in a private office setting in the United States [28]. Anxiety levels were comparable to those reported in patients undergoing invasive medical and surgical procedures.

Minimally invasive diagnostic procedures — Minimally invasive diagnostic procedures involve invasion of a body cavity or access to an internal organ. Widely varying rates of anxiety have been found at the time of procedure based on sample characteristics, type of procedure, and whether the encounter included discussion about the results.

●Prostate biopsy – In a study of 1781 men in Sweden undergoing prostate biopsy, 49 percent reported intermediate levels of anxiety, and 6 percent reported high levels of anxiety [29]. Two smaller studies, conducted in India and the United Kingdom, found similar results [30,31].

●Prenatal diagnostic procedures (chorionic villus sampling and amniocentesis) – In a study of 254 women in France undergoing invasive prenatal diagnostic procedure with either chorionic villus sampling or amniocentesis, 87 percent of the women reported experiencing anxiety about the procedure, most often from the moment they were informed that it was indicated [32].

Two case-controlled studies in England reported that women of advanced maternal age undergoing amniocentesis had significantly higher average levels of acute anxiety immediately prior to the procedure compared with women in the same gestational age who are undergoing routine ultrasound testing [33] and compared with women of advanced maternal age who chose not to undergo amniocentesis [34].

Having prenatal testing may ultimately decrease anxiety among pregnant women by providing reassurance of fetal health. A study of 179 women in England found that women who underwent amniocentesis had significantly lower anxiety in the third trimester compared with women who did not undergo amniocentesis [35].

●Gastrointestinal endoscopy – A study of 79 outpatients undergoing elective endoscopy without the use of conscious sedation found that 15 percent reported experiencing a panic attack during the procedure [36].

●Other diagnostic procedures – Elevated levels of anxiety have been reported in samples of patients awaiting or undergoing gastrointestinal endoscopy, bronchoscopy, breast biopsy, and colposcopy [37-43].

Minimally invasive treatment procedures — Minimally invasive treatment procedures involve invasion of a body cavity or access to an internal organ. Rates of anxiety vary, with estimates of prevalence between 16 and 49 percent.

●Coronary procedures – Rates of anxiety tend to be higher in patients undergoing coronary angioplasty for the first time (26 percent in first timers versus 42 percent in repeaters) [44] and in women compared with men (24 percent versus 16 percent) [45].

Anxiety levels have been found to be elevated in 16 to 49 percent of patients undergoing coronary angioplasty or stent placement, with some of the variation likely due to differences in anxiety measures and cut-off scores [44-46]. A study of 88 patients in Turkey found that patients have moderate level of anxiety on the day of coronary angiography [47].

●Laparoscopic surgery – A study of 80 patients undergoing laparoscopic cholecystectomy found that approximately 39 percent of patients experienced preoperative anxiety [48]. Patients who had a longer hospital stay prior to the surgery reported higher preoperative anxiety. A mean elevated level of anxiety was found in a sample of 57 women in the United States undergoing bilateral laparoscopic tubal ligation [49].

●Other – A study of 383 women undergoing uterine dilation and curettage found a prevalence of preoperative anxiety to be 23 percent [50]. In patients undergoing carotid endarterectomy, the prevalence of acute procedure anxiety in a sample of 120 patients was 39 percent [51].

Anxiety levels were generally low among patients undergoing cataract surgery [52,53]. Anxiety was the highest before cataract surgery but decreased immediately after surgery [53].

Major surgeries — These are typically the most invasive procedures posing the greatest risks to patients. They are usually performed under general anesthesia; thus, anticipatory anxiety is more typically of clinical concern rather than anxiety during the procedure. As example, in a study of 3087 surgical patients undergoing any kind of anesthesia and surgeries, 40 percent of patients had high preoperative anxiety [54].

●Open heart surgery – A study of 80 patients undergoing open heart surgery found that 32.5 percent reported clinically significant anxiety one day before surgery, 21.5 percent one week after surgery, and 18.7 percent at six months follow-up [55]. Females reported a greater level of anxiety then males at all assessment points.

●Neurosurgery – In a study of 109 patients undergoing brain tumor biopsy or craniotomy with resection of tumor, 30 percent of patients had clinical levels of anxiety prior to the procedure, compared with 20 percent in a comparison group of patients undergoing elective spinal surgery [56].

●Coronary artery bypass graft (CABG) – In a study of 60 patients undergoing CABG in Iran, 28 percent of patients undergoing the surgery reported moderate to high CABG-specific fear (eg, fear of CABG, fear of death, fear of pain), and overall 45 percent were moderately to highly anxious [57].

●Hip or knee arthroplasty — In patients undergoing total hip or knee arthroplasty, the baseline prevalence of anxiety in one study of 384 patients was about 19 percent [58]. The percentage of patients who were anxious decreased at 12 months postoperatively. The mean level of anxiety decreased at three months post-surgery for knee patients and at 3 and 12 months for hip patients, compared with baseline.

Procedural risk factors — For some procedures, characteristics of the procedure are associated with the level of acute procedure anxiety, including:

●Invasiveness of the procedure [59]

●Uncertainty of outcome

•Diagnostic procedures with the possibility of a malignant finding – eg, breast biopsy [43] or prostate biopsy [31]

•Possibility of needing a CABG experienced by patients undergoing angiography [46]

●More anxiety associated with treatment procedures compared with screening procedures [60]

●The quality of clinician-patient communication about the procedure [61]

●Presence or absence of sedation during the procedure [25]

●Anticipation of pain and discomfort [42,62]

●Fear of general anesthesia [63]

As examples:

●In a naturalistic study of dental phobia, 987 patients rated invasive procedures as more anxiety provoking than noninvasive procedures [59]. The least anxiety provoking were noninvasive procedures (eg, dental radiograph, dental check-up, getting molds or imprints made, teeth cleaning) and stimuli related to personnel or setting (eg, the dentist as a person, white gown, waiting room). The most anxiety provoking types of invasive dental procedures were:

•Dental surgery

•Having some gum burned away

•Root canal treatment

•Extraction of a tooth or molar

•Cutting or tearing of soft tissue

●In a study of 254 women in France undergoing an invasive prenatal diagnostic procedure, the presence of anxiety was directly associated with [32]:

•A more invasive procedure (chorionic villus sampling rather than amniocentesis)

•A more serious indication for the procedure (eg, a finding of fetal structural abnormality on ultrasonographic examination)

•The perception that information about expected pain was not fully disclosed

Comorbidities — Patients with a diagnosis of specific phobia (and possibly acute procedure anxiety) have been found to have higher rates of comorbid anxiety disorders than patients without specific phobia, including [5]:

●Agoraphobia (see "Agoraphobia in adults: Epidemiology, pathogenesis, clinical manifestations, course, and diagnosis")

●Generalized anxiety disorder (see "Generalized anxiety disorder in adults: Epidemiology, pathogenesis, clinical manifestations, course, assessment, and diagnosis")

●Panic disorder (see "Panic disorder in adults: Epidemiology, clinical manifestations, and diagnosis")

●Social anxiety disorder (see "Social anxiety disorder in adults: Epidemiology, clinical manifestations, and diagnosis")

As an example, a community-based study of 1920 individuals found that those with blood-injection-injury phobia were more likely to have had other psychiatric conditions, including marijuana abuse and dependence, major depression, obsessive compulsive disorder, panic disorder, agoraphobia, and other specific phobia [7]. Patients with high dental anxiety have been found to have higher rates of conduct disorder, agoraphobia, social phobia, alcohol dependence, or another specific phobia [64]. (See "Specific phobia in adults: Epidemiology, clinical manifestations, course and diagnosis" and "Agoraphobia in adults: Epidemiology, pathogenesis, clinical manifestations, course, and diagnosis" and "Social anxiety disorder in adults: Epidemiology, clinical manifestations, and diagnosis" and "Overview of fears and phobias in children and adolescents".)

CLINICAL MANIFESTATIONS — Acute procedure anxiety is the experience of a high level of anticipatory anxiety before a procedure and/or acute anxiety at the time of the procedure. In severe cases, anxiety may be associated with avoidance of the procedure.

Anxiety is characterized by the interaction of cognitive, physiological, and behavioral components [65]. At the cognitive level, anxiety is a feeling of apprehension of possible future threat or danger to one's personal safety or security. Physiological manifestations include physical symptoms of arousal, such as elevated heart rate, palpitations, sweating, shortness of breath, or muscle tension.

Anxiety exists on a continuum, with normal anxiety when the threat estimate is accurate, to “pathological” or clinical anxiety when the threat estimate is biased.

When anxiety is acute and severe, it may take the form of a panic attack. (See "Panic disorder in adults: Epidemiology, clinical manifestations, and diagnosis".)

Behavioral features of anxiety may include avoidance or reassurance seeking, which usually has the goal of decreasing the anxiety or escaping from the perceived threatening stimulus. (See 'Avoidance or delay of procedure' below.)

Focus of fear — The focus of fear in acute procedure anxiety can vary dependent on procedural type; foci may include:

●Concerns about the potential risks and complications of the procedure

●Perceptions of pain and discomfort during the procedure

●Fears about implications and outcomes of the procedure

●Uncertainty about illness, disability, and other factors related to the procedure

●Fear of general anesthesia that accompanies surgical procedures

As examples:

●In patients undergoing oral and maxillary surgery, some of the fearful aspects of treatment included fears of complications (eg, getting an infection), pain during treatment, and wait-time before treatment [66].

●In women undergoing colposcopy, the three most frequently endorsed concerns are about pain, discomfort, and uncertainty over what would happen during the procedure [42,62]. In a focus group of 15 women undergoing colposcopy, major reasons for anxiety before and during the procedure included [67]:

•Having received insufficient information about the abnormal pap smears

•Embarrassment and discomfort in exposing an intimate part of their body

•Pain from procedure

•Long wait-time from pap smear results to the procedure

•Impersonal approach by the medical team during the procedure

●In patients undergoing angiography, the most fearful aspects of the procedure are (in rank order) [68]:

•Fears of coronary artery bypass surgery

•Uncertainty about the illness

•Death

•Pain

•Clinical findings

•Lying flat in bed

Focus with specific phobias — When acute procedure anxiety is a manifestation of a specific phobia, the focus of fear is specific to the procedure or its immediate effects. As examples:

●In patients with claustrophobia, the main focus is fear of suffocation and fear of restriction in an enclosed space [69].

●In the magnetic resonance imaging setting, in addition to fear of suffocation and fear of restriction, patients may fear being harmed by the machine (ie, fear of having a stroke in a scanner) or fear of losing control [70].

●In patients with blood phobia, the fear at the sight of blood is typically concern about physical sensations, fear of fainting, and feelings of disgust [71].

Avoidance or delay of procedure — Avoidance or delay of a necessary medical or dental procedure is one of the main negative health consequences in patients with severe acute procedure anxiety. Rates of avoidant behavior have been documented mainly for the specific phobias [19,72], but avoidance occurs in other manifestations of acute procedure anxiety as well. Avoidance of medical procedures can delay diagnosis and treatment, and adversely affect patient outcomes [72], as illustrated in the studies below:

●Pregnant women with blood-injection-injury phobia have been found to be more fearful of childbirth and have a higher rate of elective cesarean sections, pregnancy complications (eg, preeclampsia and premature contractions), adverse obstetric outcomes (eg, premature delivery and longer hospital stays), and poorer neonatal morbidity (eg, small for gestational age) [73].

●In a study of 548 older adults, the presence of dental anxiety was associated with a greater number of missing teeth and root fragments [12]. The avoidance of dental care among HIV positive patients may delay detection of opportunistic infections [14]. Numerous studies have demonstrated that patients with dental anxiety have significantly worse oral health status compared with non-anxious individuals [11,74].

If avoidance is not possible or if a fear reaction was not anticipated prior to the procedure, then the patient may have to endure the procedure with great distress or may require treatment of the anxiety in order for the procedure to be completed [75]. (See "Treatment of acute procedural anxiety in adults".)

COURSE — In most cases of acute procedure anxiety, the anxiety tends to peak prior to the procedure and decrease immediately after the procedure. This pattern has been observed in short, prospective studies of sigmoidoscopy screening for colorectal cancer [76], colposcopy [77], neurosurgery/brain biopsy [56], percutaneous coronary intervention (PTCA) [46], cardiac surgery [55,78], image-guided breast biopsy [61], and image-guided bone or soft tissue biopsy. However, a study of PTCA that followed patients for a longer period of time after PTCA found anxiety level to be equally high six to eight months postprocedure [45].

SUMMARY

●Acute procedure anxiety is an excessive fear and/or anxiety about a medical procedure that results in acute distress in anticipation of the procedure or during the procedure, or avoidance of the procedure. The fears may be rational (eg, concern that a breast biopsy may find a malignancy) or irrational (eg, fear of suffocation during magnetic resonance imaging [MRI]).

●Studies have found acute procedure anxiety to occur among patients undergoing a wide range of screening, diagnostic, and treatment procedures, including (see 'Epidemiology' above):

•Noninvasive diagnostic procedures (see 'Screening procedures' above)

•Minimally invasive diagnostic procedures (see 'Minimally invasive diagnostic procedures' above)

•Minimally invasive treatment procedures (see 'Minimally invasive treatment procedures' above)

•Major surgeries (see 'Major surgeries' above)

●The focus of fear in acute procedure anxiety varies among individuals and by the type of procedure; foci may include concerns about the procedure’s potential risks and complications, perceptions of associated pain and discomfort, or fears of the implications and outcomes of a procedure. (See 'Focus of fear' above.)

●Acute procedure anxiety is diagnosed as a specific phobia using DSM-5 criteria when the focus of the patient’s fear or anxiety is specific to the procedure or its effects (eg, a fear of seeing blood during venipuncture or suffocating during an MRI scan). A specific phobia would not be diagnosed when the patient’s fear/anxiety is not specific to the procedure itself, but about, for example, its outcome or implications (eg, a fear that a diagnostic procedure may detect a malignancy). (See 'Specific phobias' above.)

Examples of acute procedure anxiety that is diagnosed as a specific phobia include:

•In patients with blood phobia, the fear at the sight of blood is typically concern about physical sensations, fear of fainting, and feelings of disgust.

•Dental phobia is the specific fear of going to the dentist, and the fear may be triggered by multiple stimuli in the dental office, such as sound of the drill, receiving an intraoral injection, or undergoing any dental treatment.

•In patients with MRI claustrophobia, the main focus is fear of suffocation and fear of restriction while in an enclosed space, though alternatively, patients may fear being harmed by the machine or losing control.

●The epidemiology of the specific phobias has been studied with more rigorous methods than other manifestations of acute procedure anxiety. Community-based studies have estimated that 2 to 5 percent of the general population in the United States has experienced blood-injection-injury phobia or dental phobia. The point prevalence of MRI claustrophobia has been estimated at 1.8 to 2.3 percent. (See 'Epidemiology' above.)

●Procedural risk factors associated with higher levels of anxiety include the procedure’s invasiveness, the uncertainty of the procedure’s outcome (eg, malignancy of the diagnosis, or effectiveness of the treatment), the quality of clinician-patient communication about the procedure, the patient’s anticipation of pain and discomfort, the presence or absence of sedation during the procedure, and fear of general anesthesia. (See 'Procedural risk factors' above.)