Note¶
This analysis includes a quadratic term for PMA at first oral feeding (i.e., both the variable and its square are included in the model).
Primary Analysis: pma_at_first_oral_feeding vs time_to_fof¶
Analysis of pma_at_first_oral_feeding vs time_to_fof.
Unadjusted Model Results¶
Simple quadratic regression examining the direct relationship between pma_at_first_oral_feeding and time_to_fof.
Model diagnostics warning: High multicollinearity detected (condition number > 30). Residuals may not be normally distributed (p < 0.05).
Outcome: time_to_fof Predictor: pma_at_first_oral_feeding and its square
OLS Regression Results
==============================================================================
Dep. Variable: time_to_fof R-squared: 0.021
Model: OLS Adj. R-squared: 0.012
Method: Least Squares F-statistic: 2.386
Date: Tue, 05 Aug 2025 Prob (F-statistic): 0.0943
Time: 04:28:11 Log-Likelihood: -907.91
No. Observations: 228 AIC: 1822.
Df Residuals: 225 BIC: 1832.
Df Model: 2
Covariance Type: nonrobust
================================================================================================
coef std err t P>|t| [0.025 0.975]
------------------------------------------------------------------------------------------------
const 654.8801 294.335 2.225 0.027 74.875 1234.885
pma_at_first_oral_feeding -36.4353 16.729 -2.178 0.030 -69.401 -3.470
pma_at_first_oral_feeding_sq 0.5182 0.237 2.183 0.030 0.050 0.986
==============================================================================
Omnibus: 54.456 Durbin-Watson: 1.476
Prob(Omnibus): 0.000 Jarque-Bera (JB): 94.188
Skew: 1.267 Prob(JB): 3.53e-21
Kurtosis: 4.870 Cond. No. 4.05e+05
==============================================================================
Notes:
[1] Standard Errors assume that the covariance matrix of the errors is correctly specified.
[2] The condition number is large, 4.05e+05. This might indicate that there are
strong multicollinearity or other numerical problems.
Unadjusted Plot¶
Plot showing relationship between pma_at_first_oral_feeding and time_to_fof (LOESS with CI and Quadratic prediction).
Model Variables (Adjusted Analysis)¶
Outcome: time_to_fof Indep: pma_at_first_oral_feeding 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 pma_at_first_oral_feeding and time_to_fof, 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: time_to_fof Predictors: pma_at_first_oral_feeding, gestational_age_weeks, pma_at_first_oral_feeding_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: time_to_fof R-squared: 0.157
Model: OLS Adj. R-squared: 0.126
Method: Least Squares F-statistic: 5.080
Date: Tue, 05 Aug 2025 Prob (F-statistic): 8.26e-06
Time: 04:28:13 Log-Likelihood: -890.90
No. Observations: 228 AIC: 1800.
Df Residuals: 219 BIC: 1831.
Df Model: 8
Covariance Type: nonrobust
=========================================================================================================================================
coef std err t P>|t| [0.025 0.975]
-----------------------------------------------------------------------------------------------------------------------------------------
const 729.2710 283.146 2.576 0.011 171.231 1287.311
pma_at_first_oral_feeding -38.1911 16.283 -2.345 0.020 -70.282 -6.100
gestational_age_weeks -0.2203 0.821 -0.268 0.789 -1.839 1.398
pma_at_first_oral_feeding_sq 0.5230 0.231 2.267 0.024 0.068 0.978
birth_weight_grams -0.0049 0.004 -1.153 0.250 -0.013 0.003
mechanical_ventilation_no history of mechanical ventilation -5.5083 2.030 -2.714 0.007 -9.509 -1.508
o2_device_at_36_weeks_did NOT require respiratory support at 36 weeks -2.6621 2.145 -1.241 0.216 -6.890 1.566
medicalcomplexity_Children with noncomplex chronic disease -1.0046 4.928 -0.204 0.839 -10.716 8.707
medicalcomplexity_Children without chronic disease -2.5697 3.881 -0.662 0.509 -10.218 5.078
==============================================================================
Omnibus: 79.686 Durbin-Watson: 1.653
Prob(Omnibus): 0.000 Jarque-Bera (JB): 223.726
Skew: 1.535 Prob(JB): 2.62e-49
Kurtosis: 6.759 Cond. No. 6.02e+05
==============================================================================
Notes:
[1] Standard Errors assume that the covariance matrix of the errors is correctly specified.
[2] The condition number is large, 6.02e+05. This might indicate that there are
strong multicollinearity or other numerical problems.
Adjusted Plot¶
Plot showing adjusted relationship between pma_at_first_oral_feeding and time_to_fof (LOESS with CI).
Relationship Analysis¶
Adjusted plot shows relationship.