Table 2:
Maintenance of Any Breastfeeding Predicted by Exclusive Breastfeeding Threshold Estimates and Threshold Diagnostic Statistics
| N (% of training sample) | Maintenance of any BF | Exclusive BF threshold (weeks) | Sensitivitya (%) | Specificityb (%) | Positive Likelihood Ratioc | Positive predictive valued (%) | Attributable risk reductione (%) |
|---|---|---|---|---|---|---|---|
| 590 (92.2) | 4 weeks | 3.0 | 88.6 | 82.0 | 4.9 | 100.0% | 32.3% |
| 541 (84.5) | 8 weeks | 5.0 | 83.2 | 84.8 | 5.5 | 93.7% | 35.0% |
| 486 (75.9) | 12 weeks | 8.6 | 77.4 | 76.6 | 3.3 | 97.7% | 45.9% |
| 451 (70.5) | 3 monthsf | 9.0 | 72.7 | 83.5 | 4.4 | 88.5% | 50.0% |
| 323 (50.5) | 16 weeks | 12.9 | 71.5 | 66.6 | 2.1 | 74.2% | 58.6% |
| 76 (11.9) | 20 weeks | 14.9 | 64.5 | 64.5 | 1.8 | 28.6% | 65.3% |
Sensitivity: The percent of mothers in the test sample for which the exclusive breastfeeding threshold (calculated in the training sample) correctly predicted duration of any breastfeeding through at least the specified maintenance time point.
Specificity: The percent of mothers in the test sample for which the exclusive breastfeeding threshold correctly predicted duration of any breastfeeding ending before the specified maintenance time point.
Positive Likelihood Ratio: The probability that someone who met the exclusivity threshold, also met the predicted duration
Positive Predictive Value: The percentage of mothers in the test sample who were predicted to have maintained any breastfeeding through a given time point based on the duration of their exclusivity, and truly did breastfeed to or beyond that maintenance point.
Attributable Risk Reduction: The percentage reduction in risk of failing to maintain any breastfeeding at a maintenance time point among mothers who met or exceeded the exclusivity threshold, compared to women who did not meet this exclusivity threshold. The inverse yields the number needed to treat (1/ARR).
This additional timeframe was provided as Brownell et al’s23 analysis used 3 months.