Note¶
This analysis includes a quadratic term for time_to_first (i.e., both the variable and its square are included in the model).
Secondary Analysis: time_to_first vs pma_at_full_oral_feeding¶
Analysis of time_to_first vs pma_at_full_oral_feeding.
Unadjusted Model Results¶
Simple quadratic regression examining the direct relationship between time_to_first and pma_at_full_oral_feeding.
Model diagnostics warning: High multicollinearity detected (condition number > 30). Residuals may not be normally distributed (p < 0.05).
Outcome: pma_at_full_oral_feeding Predictor: time_to_first and its square
OLS Regression Results
====================================================================================
Dep. Variable: pma_at_full_oral_feeding R-squared: 0.371
Model: OLS Adj. R-squared: 0.366
Method: Least Squares F-statistic: 66.48
Date: Tue, 05 Aug 2025 Prob (F-statistic): 2.06e-23
Time: 04:28:04 Log-Likelihood: -469.49
No. Observations: 228 AIC: 945.0
Df Residuals: 225 BIC: 955.3
Df Model: 2
Covariance Type: nonrobust
====================================================================================
coef std err t P>|t| [0.025 0.975]
------------------------------------------------------------------------------------
const 34.4876 0.517 66.712 0.000 33.469 35.506
time_to_first 0.0323 0.023 1.410 0.160 -0.013 0.078
time_to_first_sq 0.0004 0.000 1.723 0.086 -5.57e-05 0.001
==============================================================================
Omnibus: 93.523 Durbin-Watson: 1.852
Prob(Omnibus): 0.000 Jarque-Bera (JB): 372.626
Skew: 1.654 Prob(JB): 1.22e-81
Kurtosis: 8.318 Cond. No. 1.21e+04
==============================================================================
Notes:
[1] Standard Errors assume that the covariance matrix of the errors is correctly specified.
[2] The condition number is large, 1.21e+04. This might indicate that there are
strong multicollinearity or other numerical problems.
Unadjusted Plot¶
Plot showing relationship between time_to_first and pma_at_full_oral_feeding (LOESS with CI and Quadratic prediction).
Model Variables (Adjusted Analysis)¶
Outcome: pma_at_full_oral_feeding Indep: time_to_first Gestational Age Var: gestational_age_weeks Confounders: ['gestational_age_weeks', 'birth_weight_grams', 'mechanical_ventilation', 'o2_device_at_36_weeks'] Covariates: ['medicalcomplexity']
Adjusted Model Results¶
Multiple regression examining the relationship between time_to_first and pma_at_full_oral_feeding, controlling for gestational age and other potential confounders.
Model diagnostics warning: High multicollinearity detected (condition number > 30). Residuals may not be normally distributed (p < 0.05).
Outcome: pma_at_full_oral_feeding Predictors: time_to_first, gestational_age_weeks, time_to_first_sq, birth_weight_grams, mechanical_ventilation_no history of mechanical ventilation, o2_device_at_36_weeks_did NOT require respiratory support at 36 weeks, medicalcomplexity_Children with noncomplex chronic disease, medicalcomplexity_Children without chronic disease
OLS Regression Results
====================================================================================
Dep. Variable: pma_at_full_oral_feeding R-squared: 0.474
Model: OLS Adj. R-squared: 0.454
Method: Least Squares F-statistic: 24.62
Date: Tue, 05 Aug 2025 Prob (F-statistic): 7.81e-27
Time: 04:28:06 Log-Likelihood: -449.28
No. Observations: 228 AIC: 916.6
Df Residuals: 219 BIC: 947.4
Df Model: 8
Covariance Type: nonrobust
=========================================================================================================================================
coef std err t P>|t| [0.025 0.975]
-----------------------------------------------------------------------------------------------------------------------------------------
const 13.9591 3.946 3.538 0.000 6.183 21.735
time_to_first 0.0862 0.029 2.946 0.004 0.029 0.144
gestational_age_weeks 0.7175 0.133 5.386 0.000 0.455 0.980
time_to_first_sq 0.0003 0.000 1.137 0.257 -0.000 0.001
birth_weight_grams -0.0007 0.001 -1.111 0.268 -0.002 0.001
mechanical_ventilation_no history of mechanical ventilation -0.7720 0.293 -2.636 0.009 -1.349 -0.195
o2_device_at_36_weeks_did NOT require respiratory support at 36 weeks -0.3359 0.309 -1.089 0.277 -0.944 0.272
medicalcomplexity_Children with noncomplex chronic disease -0.1549 0.710 -0.218 0.828 -1.555 1.245
medicalcomplexity_Children without chronic disease -0.3232 0.559 -0.578 0.564 -1.425 0.779
==============================================================================
Omnibus: 87.532 Durbin-Watson: 1.687
Prob(Omnibus): 0.000 Jarque-Bera (JB): 268.784
Skew: 1.656 Prob(JB): 4.31e-59
Kurtosis: 7.161 Cond. No. 1.02e+05
==============================================================================
Notes:
[1] Standard Errors assume that the covariance matrix of the errors is correctly specified.
[2] The condition number is large, 1.02e+05. This might indicate that there are
strong multicollinearity or other numerical problems.
Adjusted Plot¶
Plot showing adjusted relationship between time_to_first and pma_at_full_oral_feeding (LOESS with CI).
Relationship Analysis¶
Adjusted plot shows relationship.