The Impact of Cancer – Childhood Survivors Scale (IOC-CS) is an 82-item instrument with 11 subscales that evaluates the physical, psychological, and social effects of having had cancer as a child. Responses are given on a five-point Likert scale where 1 is “Not at all” and 5 is “Very much”. A “not applicable” option is also available for the Finances subscale. This questionnaire was originally developed for use in the adolescent and young adult population.IOC-CS -- English
We validated the IOC-CS in a population of 519 childhood cancers survivors aged 18-39 who were 21 years of age or younger when diagnosed with cancer. Participants completed a collection of surveys including the IOC-CS as well as several well-known and validated health-related quality of life measures (SF-36, BSI-18, PDS, Ladder of Life). We engaged in an iterative process consisting of (1) a priori categorization of IOC-CS items by domains; (2) exploratory factor analyses to test psychometric properties of hypothesized scales; (3) item reduction; (4) re-scaling and re-testing (factor analyses); and (5) derivation and scoring of subscales. Scales were evaluated for both thematic and statistical consistency. Internal reliability was evaluated using Cronbach’s alpha. Finally, we examined intraclass-correlation coefficients (ICC) for test–retest reliability in a subset of participants.
Construct validity of the IOC-CS was evaluated by examining Pearson correlations among the various derived subscales. Based on a priori hypotheses, we evaluated external (concurrent) validity by examining correlations of each of the IOC-CS subscales with the Physical Component Score (PCS), Mental Component Score (MCS) and eight subscales of the SF-36, and the subscale and overall scores for the BSI-18, PDS and Ladder of Life. Criterion validity was evaluated by review of cross-sectional differences between subjects for expected or known differences. IOC-CS sub-scale scores were examined as they differed (or not) across gender, employment status, relationship status, education, income, cancer type and reporting current health problems. For a detailed description of the psychometric properties of the IOC-CS, please review Zebrack et al. (2010), full citation below.
All questions use a five-point Likert scale with endpoints as marked. Response values increase left to right (1-5). To determine the Impact score for each subdomain, calculate the average rating across all items in the subscale. For all items, a higher score indicates greater impact.
Finances subscale: Recode any “not applicable” responses to 1 (“not at all”), then calculate the average rating across all items in the subscale. A higher score indicates greater impact.
To cite this instrument, please use the following reference:
Zebrack B. Developing a new instrument to assess the impact of cancer in young adult survivors of childhood cancer. J Cancer Surviv .2009;3(3):174-80.
In any discussions about our validation of the IOC-CS, please use the following reference:
Zebrack BJ, Donohue JE, Chesler MA, Bhatia S, Landier W. Psychometric evaluation of the Impact of Cancer (IOC-CS) scale for young adult survivors of childhood cancer. 2010;19(2):207-18.