Reproductive Health Research, University College London, London, UK
Reproductive Health Research, University College London, London, UK.
BMJ Open. 2022 Jul 25;12(7):e060287. doi: 10.1136/bmjopen-2021-060287.
To evaluate the psychometric performance, including predictive validity, of a UK version of the Desire to Avoid Pregnancy (DAP) scale.
Prospective cohort study for psychometric evaluation.
UK.
Women in the UK aged 15 years to menopause, who were not pregnant at the time of recruitment in October 2018, were eligible. 994 women completed the baseline survey and 90.2% of women eligible for the 12-month survey participated.
The DAP scale was assessed according to key measurement properties of validity (construct (structural and hypothesis testing) and criterion (predictive)), reliability (internal consistency using Cronbach's alpha and test-retest using intraclass correlation coefficients, ICC) and differential item functioning. Item response and classical test theory methods were used.
The scale was acceptable, understandable and showed good targeting with the full range of scores captured. Construct validity was demonstrated on hypothesis testing, with odds of contraceptive use increasing threefold with each increasing DAP point (range: 0-4). Eighty per cent of women with the lowest DAP score became pregnant within 12 months, compared with <1% of those with the highest DAP score. Reliability, both in terms of internal consistency (Cronbach's α 0.96) and test-retest (ICC 0.95), was excellent. Some tests of structural validity, in relation to model fit with the item-response model, were not met, and investigations suggest further exploration of the factor structure of the DAP is required in other samples. Item 5, regarding relationship with a partner, showed differential item functioning by age, number of children and relationship group.
The UK DAP is a valid and reliable measure of women's DAP and is highly predictive of pregnancy within the next 12 months. Further evaluations should continue the assessment of the factor structure and the performance of the item relating to the partner.
评估英国版生育意愿量表（DAP）的心理计量学性能，包括预测效度。
心理计量学评估的前瞻性队列研究。
英国。
2018 年 10 月招募时未怀孕、年龄在 15 岁至绝经期的英国女性符合条件。994 名女性完成了基线调查，有 90.2%符合 12 个月调查条件的女性参加了调查。
根据效度（结构（结构和假设检验）和标准（预测））、可靠性（内部一致性使用 Cronbach 的 alpha 和测试-重测使用组内相关系数，ICC）和差异项目功能评估 DAP 量表。使用项目反应和经典测试理论方法。
该量表是可接受的，易于理解，并且具有良好的针对性，可以捕捉到整个分数范围。假设检验证明了结构效度，DAP 每增加一个点，避孕的可能性就会增加三倍（范围：0-4）。DAP 得分最低的 80%的女性在 12 个月内怀孕，而 DAP 得分最高的女性中不到 1%怀孕。可靠性方面，内部一致性（Cronbach 的α 0.96）和测试-重测（ICC 0.95）都非常好。与项目反应模型的结构有效性有关的一些测试，如模型拟合，未得到满足，研究表明，在其他样本中需要进一步探索 DAP 的因素结构。关于与伴侣关系的第 5 项，根据年龄、孩子数量和关系群体，显示出差异项目功能。
英国版 DAP 是一种有效的、可靠的生育意愿测量工具，对未来 12 个月内怀孕具有高度预测性。进一步的评估应继续评估因素结构和与伴侣相关的项目的表现。
