Abstract
INTRODUCTION: Concerns about safety and side effects from contraceptives are widespread and related to reluctance to use them. Measuring these concerns is an essential component of understanding contraceptive decision-making and guiding contraceptive and interpregnancy clinical care. METHODS: We used qualitative research and item response theory to develop and test a psychometric instrument to measure contraceptive concerns and beliefs. We developed 55 candidate scale items and tested them among 572 adolescents and adults across nine California healthcare facilities in 2019-2020. We derived a 6-item scale and assessed differences by age and social determinants of health with multivariable regression. RESULTS: In qualitative data, participants voiced both concerns and positive beliefs about contraception. Quantitative survey respondents were aged 21 years on average, and 24% were parous. Over half (54%) worried contraception has dangerous side effects, and 39% worried it is unnatural. The mean Contraceptive Concerns score, increasing with higher concerns, was 1.85 (SD: 1.00, range 0-4, α = 0.81). Items fit a partial credit item response model and met prespecified criteria for internal structure validity. Contraceptive use declined with increasing Concerns score (adjusted prevalence ratio [aPR] = 0.81 [0.72-0.92]). Scores were elevated among Black (mean: 2.06; aβ = 0.34 [0.09, 0.59]) and Multiracial or other race (2.11; aβ = 0.34 [0.02, 0.66]) respondents vs. White (1.66), but not Latinx respondents (1.81; aβ = 0.11 [- 0.11, 0.33]). Scores were also elevated among participants with lower maternal education (high school/Associate's 1.89 versus college 1.60; aβ = 0.28 [0.04, 0.53]). DISCUSSION: The psychometrically robust Concerns instrument can be used in research to measure autonomous contraceptive decision-making and to design person-centered care.