TITLE: DEVELOPMENT OF AN INSTRUMENT ASSESSING RECOVERY AFTER AMBULATORY ANESTHESIA AUTHORS: Jean Wong, MD, FRCPC, Doris Tong, MD, FRCPC, Frances Chung, MD, FRCPC, David Streiner, PhD* AFFILIATION: Department of Anesthesia, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario, M5T 2S8; *Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON INTRODUCTION: As more complex procedures on higher risk patients are performed as ambulatory surgery, it is increasingly important to evaluate patients’ recovery after their hospital discharge 1 . The purpose of this study was to develop a valid and reliable instrument to assess patients’ subjective post-discharge functional recovery after ambulatory anesthesia. METHODS: Ethics approval was obtained. The development involved four phases: item generation, item selection, reliability and validity testing. In item generation, forty patients were interviewed with open-ended questions. After incorporating input from content experts, the items were scaled and a draft questionnaire was devised containing 55 items grouped under six dimensions: basic activity of daily living (ADL), intermediate ADL, role limitation, social function, mental function, and symptom distress. In item selection, seventy-six patients were interviewed with the draft questionnaire to determine the feasibility and endorsement frequency of items. Nine items were eliminated for having an endorsement rate of >0.8 for one of their alternatives. Items were selected to optimize internal consistency (Cronbach’s α) under the chosen factors. The questionnaire was modified according to the results of factor analysis and Cronbach’s α before testing reliability. Two hundred and sixty-four patients were interviewed on the third day after the surgery by two research assistants and intraclass correlation (Cronbach’s α) was calculated. Construct validity was tested by multiple hypotheses on convergent validity, extreme groups, and discriminant validity. RESULTS: For factor analysis, diagnostic checks removing items with communalities <0.6 removed 12 items. Principal component analysis was used to extract factors. The final questionnaire: Functional Recovery for Outpatients (FROP) has 3 factors (Table). Inter-rater reliability (Cronbach’s α) was found to be 0.99. Convergent validity for FROP vs. VRS pain scores (Spearman’s correlation co-efficient, r) was found to be 0.76 and for hours of restricted activity r=0.72. Discriminant validity testing demonstrated the type of surgery was significant; the coefficients for intermediate surgery (β=0.138) and for major surgery (β=0.337) indicate that major surgery was associated with a higher FROP score. DISCUSSION: The FROP demonstrated excellent reliability, and good convergent validity for VRS pain scores and hours of restricted activity. Discriminant validity revealed that the type of surgery was the only significant variable. REFERENCES: 1. JAMA.272:619-26. Table: Variables loading on each factor Factor Variables 1 Visiting friends & relatives, social activity, driving, effect of pain on daily activity, lifting or carrying groceries, care of family, return to work, moderate exertion 2 Lower limb activities: climbing stairs, walking, bending, in/out of chair, sitting 3 General physical activity: dressing, bath/shower, lying down

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Page 1: Development of an instrument assessing recovery after ambulatory anesthesia

TITLE: DEVELOPMENT OF AN INSTRUMENT ASSESSING RECOVERYAFTER AMBULATORY ANESTHESIA

AUTHORS: Jean Wong, MD, FRCPC, Doris Tong, MD, FRCPC, Frances Chung, MD,FRCPC, David Streiner, PhD*

AFFILIATION: Department of Anesthesia, Toronto Western Hospital, 399 Bathurst Street,Toronto, Ontario, M5T 2S8; *Department of Clinical Epidemiology andBiostatistics, McMaster University, Hamilton, ON

INTRODUCTION: As more complex procedures on higher risk patients are performed asambulatory surgery, it is increasingly important to evaluate patients’ recovery after their hospitaldischarge1. The purpose of this study was to develop a valid and reliable instrument to assesspatients’ subjective post-discharge functional recovery after ambulatory anesthesia.

METHODS: Ethics approval was obtained. The development involved four phases: itemgeneration, item selection, reliability and validity testing. In item generation, forty patients wereinterviewed with open-ended questions. After incorporating input from content experts, the itemswere scaled and a draft questionnaire was devised containing 55 items grouped under sixdimensions: basic activity of daily living (ADL), intermediate ADL, role limitation, socialfunction, mental function, and symptom distress. In item selection, seventy-six patients wereinterviewed with the draft questionnaire to determine the feasibility and endorsement frequencyof items. Nine items were eliminated for having an endorsement rate of >0.8 for one of theiralternatives. Items were selected to optimize internal consistency (Cronbach’s α) under thechosen factors. The questionnaire was modified according to the results of factor analysis andCronbach’s α before testing reliability. Two hundred and sixty-four patients were interviewed onthe third day after the surgery by two research assistants and intraclass correlation (Cronbach’sα) was calculated. Construct validity was tested by multiple hypotheses on convergent validity,extreme groups, and discriminant validity.

RESULTS: For factor analysis, diagnostic checks removing items with communalities <0.6removed 12 items. Principal component analysis was used to extract factors. The finalquestionnaire: Functional Recovery for Outpatients (FROP) has 3 factors (Table). Inter-raterreliability (Cronbach’s α) was found to be 0.99. Convergent validity for FROP vs. VRS painscores (Spearman’s correlation co-efficient, r) was found to be 0.76 and for hours of restrictedactivity r=0.72. Discriminant validity testing demonstrated the type of surgery was significant;the coefficients for intermediate surgery (β=0.138) and for major surgery (β=0.337) indicate thatmajor surgery was associated with a higher FROP score.

DISCUSSION: The FROP demonstrated excellent reliability, and good convergent validity forVRS pain scores and hours of restricted activity. Discriminant validity revealed that the type ofsurgery was the only significant variable.

REFERENCES: 1. JAMA.272:619-26.

Table: Variables loading on each factorFactor Variables

1 Visiting friends & relatives, social activity, driving, effect of pain on daily activity, lifting orcarrying groceries, care of family, return to work, moderate exertion

2 Lower limb activities: climbing stairs, walking, bending, in/out of chair, sitting3 General physical activity: dressing, bath/shower, lying down