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Anesth Analg 1999;88:251
© 1999 International Anesthesia Research Society


PEDIATRIC ANESTHESIA

Validation of Measures of Parents' Preoperative Anxiety and Anesthesia Knowledge

Kathryn M. Miller, PhD*, Tim Wysocki, PhD*,||, Joseph F. Cassady, Jr., MD{dagger}, Dawn Cancel, MA{ddagger}, and Neil Izenberg, MD§

*Division of Behavioral Pediatrics and Psychology, {dagger}Department of Anesthesiology, {ddagger}Nemours Children's Clinic, Jacksonville, Florida; §Nemours Foundation Center for Children's Health Media, Wilmington, Delaware; and Departments of ||Psychiatry and ¶Anesthesiology, Mayo Medical School, Jacksonville, Florida

Address correspondence and reprint requests to Tim Wysocki, PhD, Nemours Children's Clinic, 807 Nira St., Jacksonville, FL 32207.


    Abstract
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Appendix 1
 References
 
Parents' anxiety about their children's anesthesia may adversely affect the children's outcomes and compromise the quality of informed consent. Studies of these issues have been limited by the lack of validated measures of parental anxiety and knowledge surrounding anesthesia. In the present study, we evaluated psychometric properties of the Amsterdam Preoperative Anxiety and Information Scale (APAIS) and the Standard Anesthesia Learning Test (SALT) among 85 parents who participated in an evaluation of the effects of a videotape about pediatric anesthesia. The results supported the internal consistency, test-retest reliability, and concurrent validity of both instruments and documented the equivalence of two forms of the SALT. Factor analysis supported the previously demonstrated factor structure of the APAIS, further confirming its construct validity. We conclude that the APAIS and SALT are reliable and valid measures of parental anxiety and knowledge of pediatric anesthesia that can be used for clinical and research purposes.

Implications: This study verified the reliability and validity of two questionnaires for measuring parents' knowledge and anxiety about pediatric anesthesia. These questionnaires can be used in further research on factors affecting parental anxiety and knowledge before their children's surgery.


    Introduction
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Appendix 1
 References
 
Most parents of hospitalized children experience increased levels of anxiety (1), which affects children's anxiety and coping with invasive medical procedures (2). Kain et al (3) showed that parental anxiety is directly correlated with children's preoperative anxiety. Excessive preoperative anxiety may also limit parents' benefit from the preanesthetic visit and informed consent process. Debate continues regarding the appropriate disclosure of anesthetic risk. While fulfilling requirements to provide parents with such information, this process may increase anxiety among parents.

The preanesthetic visit is a standard component of preoperative preparation that has been found to reduce anxiety (5,6), supporting the need for more comprehensive preparation programs for parents (79). Yet, few instruments for measuring parental anxiety and anesthesia knowledge have been adequately validated.

The purpose of the present study was to validate the The Amsterdam Preoperative Anxiety and Information Scale (APAIS) and the Standard Anesthesia Learning Test (SALT) for use with parents of young ambulatory surgery patients. The APAIS, a brief measure for assessing preoperative anxiety and need for information (10), has been validated for use with adult surgery patients, but not for use with parents. We developed a measure of anesthesia knowledge, the SALT, for an evaluation of a videotaped preoperative preparation program for parents. In this article, we report the psychometric properties of the APAIS and the SALT.


    Methods
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Appendix 1
 References
 
Appropriate institutional committees approved the project before data collection began. Participants were parents of children scheduled for ambulatory surgery with general anesthesia at Wolfson Children's Hospital. Parents were eligible to participate if they had a healthy child (ASA physical status I or II) scheduled for ambulatory surgery and were making a preanesthetic visit before the date of surgery. Parents employed in healthcare and parents of any child who had received general anesthesia in the previous 3 yr were excluded. Of the 276 parents approached to participate in the study, 142 met all eligibility criteria. Of those eligible, 57 declined to participate, primarily (98%) because of time constraints. Table 1 provides a description of the 85 parents who comprised the final study sample. All parents signed an institutionally approved informed consent form.


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Table 1. Characteristics of Parents and Their Children
 
Data for the present report were collected during an evaluation of an educational videotape for improving anesthesia knowledge and reducing anxiety among parents before their children's ambulatory surgery. The 85 parents who participated were randomized to one of two study groups: the experimental group viewed a 22-min videotape about pediatric anesthesia (11), and the control group viewed a similar length educational wildlife videotape (12). All participating parents completed the study measures just before and after viewing the videotapes. Parents were paid $25 for study participation. Afterward, parents and children were seen for a standard preanesthetic visit.

Measures
The Amsterdam Preoperative Anxiety and Information Scale (APAIS) (10) is a six-item self-report measure of preoperative anxiety and need for information regarding anesthesia. Respondents are asked to indicate their level of agreement with each item on a five-point Likert scale (1 = "not at all" and 5 = "extremely"). With 320 adult surgical patients, Moerman et al. (10) reported good internal consistency reliability for the anxiety subscale ({alpha} = 0.86) and somewhat more moderate internal consistency for the information subscale ({alpha} = 0.68). Their factor analysis yielded two primary factors: anxiety and need for information, which accounted for 72% of the variance in total scores (10). Correlation of the APAIS scales with the State-Trait Anxiety Inventory (STAI) (10) revealed a correlation of 0.74 between the Anxiety Scale and the STAI and a correlation of 0.16 between the Information Scale and the STAI.

Two comparable versions of the Standard Anesthesia Learning Test (SALT) (SALT I and SALT II) were developed to permit evaluation of changes in parental anesthesia knowledge over a brief period. Each version is comprised of 15 multiple-choice and true/false items covering topics such as when to stop eating and drinking before surgery, the types of anesthesia, the qualifications and role of the anesthesiologist, and expectations for the child's behavior. The two final versions of the SALT were derived from an initial pool of 25 items developed for each of two preliminary versions of the SALT. These were pilot-tested by administering them to parents of nonsurgical outpatients of a pediatric clinic. Items that were answered correctly by >85% of respondents and items that were correlated poorly with total test scores were deleted, resulting in a final pool of 15 items for the two SALT forms. Items were assigned to each SALT form in such a way as to equate total test difficulty for the two forms based on these pilot data. To control for effects related to the order of administration, the two versions of the SALT were given in counterbalanced order so that half of the parents received SALT I pretest, and the other half received SALT II, with the opposite form taken posttest.

The STAI is a well validated self-report measure of anxiety consisting of two versions, one assessing the dispositional or more stable trait of anxiety proneness, and the other assessing transient or situational anxiety (13). Each version is made up of 20 items to which respondents are asked to indicate to what degree the item describes their feelings on a four-point Likert-type scale (where 1 = "not at all" and 4 = "very much so"). As would be expected, test-retest reliabilities are higher for trait (r = 0.73–0.86) than for state (r = 0.16–0.33) anxiety (13). Because pediatric anesthesia is a discrete event, parents in the present study completed only the state anxiety items as a measure of parental anxiety about their child's anesthesia.

Statistical Analysis
Several analyses were used to evaluate the validity and reliability of the APAIS and the SALT.

The construct validity of the APAIS was examined using factor analysis. Factor analysis is a statistical technique used to identify the minimal underlying factors needed to explain the intercorrelations among the test items. The results of the present factor analysis were expected to be consistent with those of Moerman et al. (10), with two factors emerging—anxiety and need for information. Concurrent validity was evaluated by computing correlations between the STAI and the APAIS total score and subscale scores. Because the STAI and the APAIS Anxiety Scale were both developed to measure anxiety, we expected that these scales would correlate more highly than the STAI and APAIS Need for Information Scale, the latter of which is not thought to measure anxiety. Cronbach's {alpha} coefficient was calculated to assess the internal consistency of the APAIS total scale and the two subscales. Test-retest correlations were computed to examine the stability of the APAIS over time. Test-retest correlations were based only on the responses of the control group because there were expected to be decreases in the scores of the experimental group as a function of the videotape intervention.

Because two SALT forms were developed, it was important to verify the equivalence of the two forms. This was achieved by comparing parents' mean scores on the two versions of the SALT using a t-test for independent samples. The equivalence of the two forms would be supported by failure of the t-test to reveal a significant difference between the mean scores of parents who completed the SALT I at pretest versus parents who completed the SALT II at pretest. Split-half reliability was used to evaluate the internal consistency of the SALT, whereas test-retest correlations were used to determine the reliability of the SALT over time. The concurrent validity of the SALT was examined by correlating parents' scores on the SALT to scores on the APAIS Need for Information Scale.


    Results
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Appendix 1
 References
 
APAIS
Principal components factor analysis revealed that two factors, explaining 75% of the variance, could efficiently describe the APAIS. The resulting factors were consistent with those previously reported: anxiety (Items 1, 2, 4, and 5; with an eigenvalue of 3.14) and need for information (Items 3 and 6; with an eigenvalue of 1.35) (10).

The reliability of the APAIS and its factors was evaluated by computing internal consistency coefficients and test-retest correlations. Internal consistency was evaluated using Cronbach's {alpha}, resulting in {alpha} values of 0.87 and 0.82 for the total scale and the Anxiety Subscale, respectively. The need for information items revealed a slightly lower {alpha} of 0.75. Pre- and posttest scores of the control group were used to evaluate the test-retest reliability. The experimental group (anesthesia video) was not included in this analysis because the APAIS scores were expected to decrease after intervention. Test-retest analyses for the total scale (r = 0.92, P < 0.001) and anxiety factor (r = 0.91, P < 0.001) revealed excellent reliability, whereas the need for information items (r = 0.62, P < .001) demonstrated moderate reliability. Although statistically significant, the reliability estimates for the need for information items may have been weaker because the scale consisted of only two items.

Concurrent validity was evaluated by comparing parents' responses on the APAIS with their responses on the STAI anxiety items. At baseline, the correlation between the APAIS anxiety items and the STAI was 0.56 (P < .001), whereas the correlation between the APAIS need for information items and the STAI was 0.19 (P = not significant [NS]). The significant correlation between the anxiety items and the STAI supports the notion that both scales measure anxiety. At the same time, the moderate correlation suggests that the APAIS anxiety items may assess anxiety that is more unique to the preoperative situation and that may not be captured by the STAI. The nonsignificant correlation between the need for information items and the STAI indicates that the former scale measures something other than anxiety. Within the APAIS, however, the Anxiety and the Need for Information Scales were moderately correlated (r = 0.35, P < 0.005). The significance of this correlation likely reflects the fact that both scales measure aspects of the preoperative situation, and the moderate strength indicates that the items are not measuring the same constructs. This interpretation is consistent with the factor analysis that indicated that APAIS measures two independent constructs.

Relationships between change scores on the APAIS and the STAI were also explored for parents in the video intervention group. Change in parents' scores on the APAIS Anxiety Scale was positively and significantly related to change in STAI scores (r = 0.58, P < 0.001). Change in parents' scores on the APAIS Anxiety Scale was also positively and significantly related to change in scores on the APAIS Need for Information Scale (r = 0.59, P < 0.001). Finally, change in parents' STAI scores was positively and significantly related to their scores on the APAIS Need for Information Scale (r = 0.37, P < 0.02). Thus, as parents' general and specific preoperative anxiety decreased, so did their desire for specific preoperative information.

SALT
The two comparable forms of the SALT were developed to be similar in content, format, and item difficulty. A t-test for independent samples was computed to verify the equivalence of the two forms. There was no significant difference in anesthesia knowledge of parents who received SALT I at baseline compared with that of parents who received SALT II at baseline (t [83] = -0.78, P = NS), which indicates that the two forms are generally equivalent in difficulty. The mean (±SD) score of parents who received SALT I at baseline was 10.95 ± 2.38, whereas the mean score of parents who received SALT II at baseline was 11.33 ± 2.07.

The reliability of the SALT was evaluated by computing split-half reliability coefficients and test-retest correlations. Guttman split-half reliability coefficients for SALT I and II were 0.56 and 0.45, respectively. The reliability of SALT I and II was further evaluated through test-retest correlations using the scores of the control group only. The test-retest correlation was 0.56 (P < 0.001), with the data combined for both administration sequences.

The concurrent validity of the SALT as a measure of anesthesia knowledge was explored by evaluating its relationship to the APAIS need for information items. Parents' levels of anesthesia knowledge (SALT scores) were not significantly related to their APAIS Need for Information Scale scores at pretest (r = 0.04, P = NS). Similarly, there was no significant relationship between changes in parents' knowledge and parents' APAIS Need for Information Scale scores in either the control (r = -0.11, P = NS) or the video intervention group (r = 0.01, P = NS). Thus, objective changes in parents' knowledge were unrelated to their subjective need for information. Parents' levels of anesthesia knowledge were also not significantly related to their general (r = -0.19, P = NS) and specific preoperative anxiety, (r = -0.13, P = NS). Similarly, changes in parental anesthesia knowledge were not significantly related to changes in STAI (r = -0.03, P = NS) or APAIS Anxiety Scale scores (r = -0.14, P = NS). The lack of significant relationships with these scales suggests that the SALT measures a construct that is independent of both anxiety and need for information about anesthesia.


    Discussion
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Appendix 1
 References
 
In this study, we evaluated measures of anesthesia knowledge (SALT) and anxiety (APAIS) for use with parents of children scheduled for surgery.

Consistent with previous findings with adults (10), two clear factors emerged on the APAIS: anxiety and need for information. The total scale, as well as the two subscales, showed adequate internal consistency and test-retest reliability. The significant correlation between the APAIS Anxiety Scale and the STAI at baseline supports its concurrent validity. The nonsignificant correlation between the APAIS Need for Information Scale and the STAI, as well as the above factor analytic results, confirm its discriminant validity such that the Need for Information Scale measures something about the preoperative situation that is unique from anxiety about anesthesia.

We have previously shown that the APAIS is sensitive to a videotape intervention aimed at preparing parents for their child's anesthesia (14). Specifically, parents who received the videotape intervention had reduced anxiety and need for information, whereas parents in the control group did not. Moreover, the present results showed that change in general and specific preoperative anxiety among parents who saw a videotaped anesthesia preparation program was significantly related to the change in their desire for specific preoperative information. Parents who reported less anxiety also reported a decrease in their need for information.

Parents in the present sample reported greater anxiety and greater need for information regarding anesthesia and surgery than did adult patients scheduled for their first surgeries (10). Although statistical analysis of these results was not possible, the difference in mean scores was approximately 0.5 SD for anxiety and almost 2 SD for need for information. This finding suggests that parents of pediatric surgery patients experience greater levels of anxiety and need for information than do adults who are undergoing surgery themselves. It is important to remember, however, that the APAIS was originally developed and tested in Europe, whereas the present study was conducted in the United States. Thus, it is also possible that the apparent difference in anxiety and need for information levels reflects a demographic difference between these samples, rather than a difference related to who is the respondent on the APAIS.

This is the first article to report the psychometric properties of the SALT. The two SALT versions were equivalent in difficulty at baseline. Test-retest and split-half reliability estimates for the SALT were in the moderate range. Although these results may raise concerns regarding the stability of the measure, there are several issues that may account for the moderate reliability. With regard to test-retest reliability, the method for computing test-retest reliability in the present study was somewhat unconventional: rather than measuring the test-retest reliability of the same version of the SALT, the correlation was measured between one version of the SALT pretest with the other version of the SALT posttest. We did not use the same version of the SALT pre- and posttest in an effort to avoid practice effects. The resulting correlation is not very high, but using the same version of the SALT both pre- and posttest would likely reveal stronger test-retest reliability. In terms of the internal consistency estimate, each version is comprised of 15 items tapping different aspects of anesthesia for children. It is quite likely that these items would cluster into two or more factors that reflect these different aspects of anesthesia (e.g., types of anesthesia, preoperative preparation). The internal consistency of these factors would be expected to be greater than that for the total scale, but the subject to variable ratio in this study did not permit a valid factor analysis to be conducted for the SALT. Additional studies with larger samples are needed to explore the underlying factor structure of this measure. Because SALT I had stronger internal consistency than SALT II, we recommend using SALT I when administration of both forms is unnecessary.

Neither parents' anesthesia knowledge pretest nor their change in anesthesia knowledge was significantly correlated with parents' pretest and change scores for preoperative anxiety and need for information. The lack of a significant relationship between changes in parental knowledge and their desire for anesthesia information may suggest that, even after being provided basic information regarding pediatric anesthesia, parents still desire more information about pediatric anesthesia for their children. For example, parents may desire more detailed information about their children's scheduled surgical procedures. Because the SALT specifically measures knowledge about anesthesia, changes in factual knowledge about anesthesia would not be expected to influence parents' perceived need for information about other aspects of the surgery.

One limitation of the present study is that the sample consisted primarily of mothers (94%). Unfortunately, the limited number of fathers in the present sample did not allow independent assessment of the validity of the APAIS and SALT separately for mothers and fathers. Although the findings did not change when fathers' responses were excluded from the data analyses, it is recommended that caution be taken when interpreting the present findings with regard to fathers. Given that previous research has documented gender differences on the APAIS (10), future research efforts should be directed toward obtaining representative samples of both mothers and fathers to study gender effects in parents on the APAIS and the SALT.

In the present article, we provide initial support for the APAIS and the SALT as measures of preoperative anxiety, need for information, and anesthesia knowledge to be used with parents of pediatric ambulatory surgery patients. Additional research and refinement of the measures could strengthen their psychometric properties. Given that the pediatric anesthesiologists' time is limited, the APAIS could be used as an efficient tool for identifying parents who are particularly anxious or in need of information regarding their child's anesthesia. Because parental anxiety can influence children's coping with medical procedures, proactive education may reduce the negative postoperative outcomes caused by anxiety. In addition to uses in evaluations of programs for preparing parents of children undergoing anesthesia and surgery, the APAIS and the SALT may provide meaningful data for a variety of research questions, such as how parental preoperative anxiety and knowledge influence children's adjustment to surgery and whether parental anxiety and anesthesia knowledge affect the quality of the informed consent process.


    Appendix 1
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Appendix 1
 References
 
Standard Anesthesia Learning Test (SALT)
Version I: SALT I

The following questions should be answered "true" or "false"

Version I: SALT II

The following questions should be answered "true" or "false"


    Acknowledgments
 
This work was supported by Nemours Foundation Grant 20.8949.


    References
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Appendix 1
 References
 

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  2. Harbeck-Weber C, Hepps McKee D. Prevention of emotional and behavioral distress in children experiencing hospitalization and chronic illness. In: Roberts MC, ed. Handbook of pediatric psychology. New York:Guilford, 1995:167–84.
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  11. Nemours Foundation. Your child's anesthesia [videotape]. Wilmington, DE: Nemours Foundation Center for Biomedical Communication, 1995.
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  13. Spielberger CD, Gorsuch RL, Lushene RE. State-Trait Anxiety Inventory Manual. Palo Alto, CA:Consulting Psychologists Press, 1970.
  14. Cassady JF, Wysocki T, Miller KM, et al. Use of a preanesthetic video for facilitation of parental education and anxiolysis prior to pediatric ambulatory surgery. Anesth Analg 1998;88:246–50.[Abstract/Free Full Text]
Accepted for publication September 23, 1998.




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Lippincott, Williams & Wilkins Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999 HighWire Press