Frequency of preoperative anxiety in Pakistani surgical patients.
ABSTRACT To measure the frequency of preoperative anxiety in patients coming to our hospital and to correlate Visual analogue scale (VAS) with State Trait Anxiety Inventory (STAI) questionnaire.
This cross sectional study included 300 ASA I and II adult surgical in-patients admitted over a period of one year. STAI questionnaire and VAS was used as study tools. STAI score of > 44 or VAS score of > or = 50 were considered as significant anxiety. Enrolled patients were visited by primary investigator the day before surgery and patients were asked to fill the STAI questionnaire and VAS score.
Significant preoperative anxiety was seen in 62% patients (73% females and 42% males). Frequency of anxiety decreased with advancing age but increased with higher educational status. A total of 77% of patients with no previous exposure to surgery and 26% of patients who had previous surgery, were anxious. Also 49% of patients who had visited the clinic and 86% of patients who had not visited the clinic were anxious. VAS correlated with STAI in 90% cases. Cut off value of VAS which showed positive correlation with STAI was 45.
Frequency of preoperative anxiety was 62%. Female gender, younger age and higher educational status were positively correlated while prior experience of surgery while preoperative anaesthesia clinic visit were negatively correlated with anxiety. VAS correlated well with STAI.
The assessment of anxiety is important in patients
scheduled for surgery because anxious patients respond
differently to anaesthesia than non anxious patients. Anxious
patients require higher doses of induction agents and
postoperative analgesic drug.1-4Literature suggests the
incidence of preoperative anxiety as 60 to 80 % in western
population.5,6The frequency of anxiety in Pakistani surgical
patients is not known. Cultural differences may affect this
There are several instruments for measuring anxiety.
Objective estimates include indirect measurements of
sympathetico-adrenal activity using heart rate and blood
pressure, or skin conductance, while plasma cortisol and
urinary catecholamines have been used as more direct
measurements of this activity.6,7Subjective tools that can be
used for anxiety assessment are STAI (State Trait Anxiety
Inventory), HADS (Hospital Anxiety and Depression Scale),
VAS (Visual Analogue Scale) and others.8
The current gold standard of anxiety measurement is
Spielberger's State-Trait Anxiety Inventory (STAI).9STAI has
two versions, one is for assessment of trait anxiety (T-STAI)
and other is for assessment of state anxiety (S-STAI).
Measurement of state anxiety is recommended in perioperative
period. Visual analogue scale is an alternative scale which
consists of 100 mm line.10One end of this line shows no
anxiety while the other end illustrates the highest anxiety
possible. Anaesthetists are familiar with this tool as it is also
used in pain measurement.
Purpose of our study was to identify the frequency of
anxiety in a group of Pakistani surgical patients presenting to
our hospital using both State Version of State Trait Anxiety
Inventory Scale (S-STAI) and Visual Analogue Scale (VAS)
taking S-STAI as gold standard. The correlation of S-STAI
with VAS was also noted.
Patients and Methods
After approval from hospital's ethical committee, this
cross sectional study was conducted on the surgical wards of
Aga Khan University Hospital Karachi. Duration of study was
one year (from April 1st 2005 till April 30, 2006).
A total of 300 patients were enrolled by convenient
sampling technique. Those included in the study were adult
ASA I and II admitted patients (age between 16 - 80 years)
undergoing various elective surgeries. Patients with known
psychiatric illness, those on any type of anxiolytics and those
who did not understand Urdu or English were excluded from
the study. In addition, procedures like cardiothoracic surgery,
major vascular surgery, surgery for malignancies and extensive
bowel resection were also excluded.
The study tools used were the State version of State
Trait Anxiety Inventory (S-STAI)9and Visual analogue scale.10
S-STAI consists of 20 statements. Ten statements express
anxiety while the remaining 10 statements represent the
relaxed and pleasant state of patient if there is any. These
statements are arranged randomly as described in the original
359J Pak Med Assoc
Frequency of preoperative anxiety in Pakistani surgical patients
Mohammad Faisal Jafar, Fauzia Anis Khan
Department of Anaesthesia, Aga Khan University Hospital, Karachi.
Objective: To measure the frequency of preoperative anxiety in patients coming to our hospital and to correlate
Visual analogue scale (VAS) with State Trait Anxiety Inventory (STAI) questionnaire.
Methods: This cross sectional study included 300 ASA I and II adult surgical in-patients admitted over a period
of one year. STAI questionnaire and VAS was used as study tools. STAI score of > 44 or VAS score of > 50 were
considered as significant anxiety. Enrolled patients were visited by primary investigator the day before surgery
and patients were asked to fill the STAI questionnaire and VAS score.
Results: Significant preoperative anxiety was seen in 62 % patients (73% females and 42% males). Frequency
of anxiety decreased with advancing age but increased with higher educational status. A total of 77% of patients
with no previous exposure to surgery and 26% of patients who had previous surgery, were anxious. Also 49% of
patients who had visited the clinic and 86% of patients who had not visited the clinic were anxious. VAS
correlated with STAI in 90% cases. Cut off value of VAS which showed positive correlation with STAI was 45.
Conclusion: Frequency of preoperative anxiety was 62%. Female gender, younger age and higher educational
status were positively correlated while prior experience of surgery while preoperative anaesthesia clinic visit were
negatively correlated with anxiety. VAS correlated well with STAI (JPMA 59:359; 2009).
scale. In front of each statement there are four responses.
Patients have to pick any one response for each statement. We
used English version of STAI for patients who understood
English and a translated Urdu version of STAI for those who
did not understand the English questionnaire. A value of more
than 44 on this scale was taken as significant anxiety. The
second scale used was Visual Analogue Scale for anxiety
(VAS).10It consists of a 100 mm straight line. Left side of this
line is marked as "No anxiety "and "0" while extreme right of
this line is marked as "maximum anxiety" and "100" .Patients
were requested to assess their own anxiety and make a
corresponding mark on the anxiety line accordingly.
A proforma with three parts was designed for the study.
Part 1 contained demographic data including name, age,
gender, medical record number, level of education, occupation,
current surgery scheduled, information about any previous
surgeries and whether the patient was seen in the preoperative
clinic. Part 2 contained S-STAI scale and Part 3 contained
VAS. Eligibility of patients for study was established by the
primary investigator after reviewing the patients who were
scheduled on next day operating room list. Recruited patients
were then visited by primary investigator on the evening before
surgery between 17:00 hrs and 21:00 hrs. After explaining the
purpose of the study and instructions for filling STAI and VAS,
written informed consent was obtained and demographic data
was recorded by the primary investigator. Patients were then
asked to fill the forms in the presence of primary investigator.
A standardized time of 10 minutes was given to the patient to
fill the proforma.
Frequency tables were generated for age, gender,
occupation, level of education, type of surgery, exposure to past
surgery and visit to preoperative clinic. In addition mean and
standard deviation for age was calculated.
Two sided Chi square test was used to determine the
gender/age/preoperative clinic visit/past exposure to
surgery/type of surgery/level of education. A p value of <0.05
was considered significant.
between anxiety and
One way analysis of variance (ANOVA) was used to
compare the combined effect of prior surgery and anaesthesia
clinic visit on preoperative anxiety.
Correlation between STAI and VAS was calculated by
applying Pearson test of correlation and linear regression graph.
Cut off value for VAS against STAI score of 44 was
determined by obtaining coordinates from receiver operating
characteristic curve (ROC curve). The value with highest
possible specificity and sensitivity was then chosen.
A total of 300 patients were enrolled in the study. Their
mean age was 42±16 years (range 16 to 80 years). There were
108 (36%) males and 192 (64%) females. As regards level of
education, 69 (23%) were Matriculate or less, 146 (48%) were
intermediate and 85 (28.3%) were graduate or above.
Ninety one (30%) patients had undergone previous
surgery while 209 (70 %) had no experience of previous
The preoperative anaesthesia clinic was visited by 197
(66%) patients for the present surgery. Distribution of patients
according to occupation and, surgical specialty is given in
Tables 1 and 2 respectively.
Factors affecting anxiety levels:
Over all 186 (62 %) patients had significant
preoperative anxiety (having S-STAI scores of 44 and above).
Females were found to be more anxious than males with
preoperative anxiety being present in 141 (73%) women
compared to 45 (42%) males (p< 0.001).
Age was found to be a contributing factor in predicting
preoperative anxiety levels. As age increased, the anxiety
frequency decreased (p< 0.001).
Effect of occupation on preoperative anxiety levels
were not analyzed because of uneven distribution of patients
and gender in this subgroup.
There was significant correlation (p=0.005) between
level of education and preoperative anxiety. Patients with
educational level Matriculate or less, 33 (48%), had significant
preoperative anxiety. This increased to 95 (65%) in the group
Vol. 59, No. 6, June 2009360
Table 1: Patient Distribution According to Occupation.
Table 2: Patient Distribution According to Type of Surgery.
who had completed intermediate level of education. Highest
frequency of anxiety was seen in 58 (68%) patients and it was
more in postgraduates.
There was clinically and statistically significant
correlation between anxiety and different types of surgery.
However correlation between type of surgery and preoperative
anxiety was not included in the results because of uneven
distribution of female gender and housewife occupation in
surgical subsets (which were independent risk factors for
anxiety) which could have confounded the results.
Among those patients who had no experience of prior
surgery, 162 (77%) had significant anxiety. Frequency of
preoperative anxiety was only seen in 24 (26%) patients who
had undergone at least one surgery in the past (p < 0.0001).
Patients who visited the preoperative clinic had a low
frequency of anxiety. Only 97 (49%) patients out of those who
had visited the clinic were anxious. On the other hand 89 (86%)
patients who had not visited the clinic were anxious (p < 0.001).
Combined effect of previous surgery and preoperative
clinic visit on anxiety was also analyzed. Patients who neither
visited the clinic nor had past experience of surgery numbered
84 (92%), had preoperative anxiety. Whereas 5 (42%) patients
who had previous surgery only (and not visited the clinic for
present surgery) were anxious. Seventyeight (66%) patients
who only visited the clinic group (but had no exposure to
previous surgery) were anxious. On the contrary, only 19
(24%) patients who had both previous surgery and had visited
the clinic for present surgery, had anxiety. Statistical analysis
between these four groups (one way ANOVA) showed that a
combination of previous exposure to surgery and preoperative
clinic visit for present surgery was more effective in
determining low frequency of anxiety than when these were
present individually ( p < 0.01).
Comparison of STAI and VAS scales:
VAS was compared against STAI scale to see the
correlation between two scales.
A linear association was observed between the two
scales for 90% of readings. (r2= 0.90) (Graph). Cut off value of
VAS which showed positive correlation with STAI score of 44
was found to be 45. Using VAS to measure anxiety with this
cutoff value, frequency of anxious patients was 62%. This was
similar to the results obtained by STAI questionnaire
(frequency of anxiety with STAI was also 62%).
Anxiety is a common response to stress and is present
in patients scheduled for surgery. As with pain, assessment of
presence of anxiety and quantifying is difficult. In the past,
various investigators described different methods for
quantifying anxiety. In broad terms these were either self
reporting questionnaires9-13or objective tools which measured
the activity of stress hormones.6All these methods have their
limitations. Among the available tools, State Trait Anxiety
Inventory questionnaire (STAI)9is currently taken as a gold
standard because it has shown consistent results in different
population and ethnic groups in assessing anxiety and is
available in various languages. Major drawback is that it is
cumbersome with a total of 20 questions, patient should be
literate to understand and fill it, and it needs some explanation
for the patient. Various other scales were developed and tested
against STAI. One of the simple scale for use is Visual
Analogue Scale (VAS) which consists of 100 millimeters
straight line with 0 on its extreme left and 100 on the extreme
right position.10This scale is simple and self explanatory and
can easily be filled by any patient who is familiar with
numericals. Literature suggests that it correlates well with
STAI and can be used to determine anxiety.8,10,13
Anaesthesiologists are also familiar with this scale because of
its use in pain measurement.
Over all frequency of preoperative anxiety in our study
was 62% as suggested by STAI score of more than 44. This
result was similar to the previous studies done in western
We also observed that females were more anxious than
males. Some previous studies support this finding1,10,14,15while
others found that gender was not a determinant of preoperative
Higher education was found to be related to higher
anxiety levels. These observations are supported by Domer et
361 J Pak Med Assoc
Graph: Correlation between VAS and STAI
Linear Regression Graph.
al14and Caumo15but not by other studies.10,16It is likely that
patients with higher level of education were more aware of the
complications related to surgery and anaesthesia. It was also
observed in the prior studies that in educated patients,
information seeking behaviour was more frequent and this in it
self was associated with high level of anxiety.1
In our study, increasing age was associated with a
decreased level of preoperative anxiety. Our results are similar
to Kindler10and Iftikhar uddin16but different from Domer and
colleagues14who did not find age as a determinant of
Visit to the preoperative anaesthesia clinic was found to
be helpful in reducing anxiety before surgery. This was
consistent with some studies,13,17in contrast, one study found
no correlation between visit to preoperative clinic and level of
preoperative anxiety.18It is apparent that explanation and
reassurance by anaesthesiologist in the preoperative clinic,
might be beneficial to reduce anxiety and fear.
Another factor which was negatively correlated with
anxiety was prior experience of surgery. Patient who had at
least one prior surgery had low anxiety levels. This finding was
also consistent with other studies reported by Moerman,1
Kindler10and Caumo.15These results suggest that patients who
had undergone another surgery earlier were less anxious
because they had less "fear of unknown" or misconcepts about
anaesthesia and surgery.1
We also observed that combination of factors (previous
exposure to surgery and visit to the preoperative anaesthesia
clinic visit for the present surgery) was more effective in
reducing anxiety than when they were present individually.
Unfortunately, valid statistical analysis of association
between anxiety and type of surgery and occupation was not
possible in our study because of two reasons. First, all the
patients in gynecological and obstetrical surgeries were
females and we found female gender itself a major predictor of
preoperative anxiety. Second, majority of these females were
housewives occupation subgroup.
In addition, distribution of different occupation was not
uniform in our study and majority of patients were housewives
in gynaecological / obstetrical surgery group. Highest level of
anxiety was found in obstetrical surgery followed by
gynecological surgery and rest of surgical subsets were less
anxious. Lowest frequency of anxiety was found in
In some prior studies done by Moerman et al1and
Boker et al,13type of surgery was not important in predicting
preoperative anxiety while in one study done by Kindler et al,10
otolaryngological and thoracic surgeries were associated with
higher level of anxiety.
One critique on our study is that we recorded
observations for anxiety levels on the evening before surgery
and our results are based on this, there is a possibility that
anxiety level in the preoperative area just before surgery may
show different results. A study by Lichtor et al19stated that
irrespective of timing of recording of anxiety, the frequency and
level of anxiety remained the same. Some of the other factors
which were found to be related to anxiety in other studies were
preference of presence of accompanying person with patient14
and information seeking behaviour.1We did not study these
factors. Another critique is that we have taken the cutoff for
significant anxiety based on previous studies in Western
population and may not be the cutoff for the local population.
We were unable to locate any such study in the local population.
This can be an area of further research. Till such research is
available Western standards will need to be applied.
Finally, we observed the correlation between STAI and
VAS scale and found that low STAI scores were associated
with low VAS scores and vice versa. We retrieved the cutoff
value of VAS score of 45 for deciding the presence or absence
of anxiety. This value was derived against STAI score of 44
taking STAI as gold standard for measurement of anxiety.
Literature suggests slightly higher cutoff value (i.e. VAS score
of 50).8Reason of this higher value in a study by Millar et al9
may be because majority of their scores on VAS scale clustered
around score of 50. No such clustering of data at any specific
score was observed. However, frequency of anxiety was
identical (i.e. 62%) in our study irrespective of the use of VAS
or STAI. Because of excellent correlation between VAS and
STAI, it is recommended that either scale can be used to assess
anxiety before surgery.8,10,13
In the presented study, over all frequency of
preoperative anxiety was 62%. Factors which were positively
correlated with anxiety were female gender, younger age and
higher education level. Factors which were shown to reduce
anxiety were prior experience of surgery and preoperative
anaesthesia clinic visit. It was also observed that Visual
Analogue Scale correlated well with State Trait Anxiety
Inventory and either scale can be used to assess anxiety in our
preoperative surgical patients.
The contribution of Mr Iqbal Azam for statistical help
and Dr Mohammad Ali, Senior instructor, for literature search
and formatting the article is acknowledged with gratitude.
1.Moerman N, Vandam FS, Muller MJ, Oosting H. The Amsterdam Preoperative
Anxiety and Information Scale (APAIS). Anesth Analg 1996; 82:445-51.
2. Ng EH, Miao B, Ho PC. Anxiolytic premedication reduces preoperative anxiety
and pain during oocyte retrieval.Hum Reprod 2002; 17: 1233-8.
3.Maranets I, Kain ZN. Preoperative anxiety and intraoperative anesthetic
Vol. 59, No. 6, June 2009362
requirements. Anesth Analg 1999; 89:1346-51.
Kain ZN, Sevarino F, Alexander GM, Pincus S, Mayes LC. Preoperative anxiety
and postoperative pain in women undergoing hysterectomy. A repeated-measures
design. J Psychosom Res 2000; 49:417-22.
5. Shevde K, Panagopoulos G. A survey of 800 patients knowledge, attitudes and
concerns regarding anesthesia. Anesth Analg 1991; 73:190-8.
6. Hicks JA, Jenkins JG. The measurement of preoperative anxiety. J R Soc Med
7. Wallin BG. Neutral control of human skin blood flow. J Auton Nerv Syst 1990;
8. Millar K , Jelecic M, Bonke B, Asbury AJ. Assessment of preoperative anxiety:
comparison of measures in patients awaiting surgery for breast cancer. Br J Anesth
9. Spielberger CD, Gorsuch RL, Lushene RE. State trait anxiety inventory manual.
Palo Alto, CA: Consulting Psychologists Press, 1970.
10. Kindler CH, Harms C, Amsler F, Ihde-Scholl T, Scheidegger D. The visual
analogue scale allows effective measurement of preoperative anxiety and
detection of patient's anesthetic concerns. Anesth Analg 2000; 90:706-12.
11. Zigmond AS, Snaith RP. The Hospital Anxiety and Depression Scale.Acta
Psychiatrica Scandinavica 1983; 67:361-70.
12. Kain ZN, Mayes LC, Cicchetti DV, Bagnall AL, Finley JD, Hofstadter MB. The
Yale preoperative anxiety scale, how does it compare with a gold standard?
Anesth Analg 1997; 85:783-8.
13. Boker A, Brownell L, Donen N. The Amsterdam preoperative anxiety and
information scale provides a simple and reliable measure of preoperative anxiety.
Can J Anesth 2002; 49: 792-8.
14. Domar AD, Everett LL, Keller MG. Preoperative anxiety: is it a predictable entity?
Anesth Analg 1989; 69:763-7.
15. Caumo W, Schmidt AP, Schneider CN, Bergmann J, Iwamoto CW, Bandeira D,
et al. Risk factors for preoperative anxiety in adults. Acta Anaesthesiol Scand
2001; 45: 298-307.
16. Iftikhar uddin, Abdullah K, Tahir J, Rahila I. Pre-operative anxiety in patients
admitted for elective surgery in King Saud hospital, Unaizah, Al-Qassim
Kingdom of Saudi Arabia. Pak J Med Sci 2002; 18: 306-10.
17. Klopfenstein CE, Forster A, Van Gessel E . Anesthetic assessment in an outpatient
consultation clinic reduces preoperative anxiety. Can J Anaesth 2000; 47: 511-5.
18.Task Force on DSM-IV, American Psychiatric Association. Anxiety disorders. In:
Diagnostic and Statistical Manual of Mental Disorders. 4th ed, text revision.
Washington DC: American Psychiatric Pub Inc 2000; pp 429-84.
19.Lichtor JL, Johanson CE, Mhoon D, Faure EA, Hassan SZ, Roizen MF.
Preoperative anxiety: Does anxiety level the afternoon before surgery predict
anxiety level just before surgery? Anesthesiology 1987; 65: 595-9.
363J Pak Med Assoc