Selecting a cutoff point for a developmental screening test based on overall diagnostic indices and total expected utilities of professional preferences.
OBJECTIVE
A cutoff point in a test with sounded validity and professional preferences can help to make an accurate clinical decision. This study aimed to determine a cutoff point between two strategies for a developmental screening checklist (referred to as Taipei II). Cutoff point A was set as one or more item failed and cutoff point B was set as two or more items failed or one or more marked item failed.


METHODS
This study was based on the total expected utilities of professional preferences and overall diagnostic indices. A self-administered questionnaire was developed to collect the estimated utility from professionals involved in early childhood interventions (n = 81) regarding four screening outcomes (probabilities of true positive, false positive, true negative, or false negative) and costs. The total expected utilities were calculated from the probabilities of four screening outcomes and utility values.


RESULTS
The diagnostic odds ratio was higher for strategy B (695 and 209, respectively) than that of strategy A (184 and 150, respectively) when using the Taipei II on children under 3 years of age and age 3 and over. Strategy B also had a higher median total expected utilities score than strategy A (0.78 vs. 0.72 for children < 3 and 0.76 vs. 0.67 for children > or = 3).


CONCLUSIONS
If only one cutoff point can be chosen, the authors suggest that clinicians should choose cutoff point B when using the Taipei II for screening. However, two cutoff points of Taipei II, a combination of strategy A and B, can also be used clinically.
Liao
Hua-Fang
HF
School and Graduate Institute of Physical Therapy, National Taiwan University, Taipei, Taiwan.
Cheng
Ling-Yee
LY
Hsieh
Wu-Shiun
WS
Yang
Ming-Chin
MC
D057189:Checklist / Q000191:economics / Q000295:instrumentation / Q000592:standards*; D002675:Child, Preschool; D002658:Developmental Disabilities / Q000145:classification / Q000175:diagnosis*; D004467:Economics; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires