. 2021 Mar 10;12:633533. doi: 10.3389/fpsyg.2021.633533

TABLE 4.

Unconditional latent growth model fit statistics, unstandardized means, and variances.

Model	χ ²	df	p value	TLI	CFI	RMSEA	SRMR	AIC	BIC	90% CI RMSEA		Model Comparison	Δχ ²	Δ df	Δ CFI
										LL	UL
Study resources
M0. Intercept only	86.02	27	0.00	0.92	0.91	0.13	0.12	283.25	333.38	0.096	0.155	M3 vs. M0	−27.94*	0	0.07
M1. Linear	92.22	31	0.00	0.91	0.92	0.12	0.11	279.40	317.74	0.091	0.147	M2 vs. M1	−57.77*	−4	0.06
M2. Quadratic	37.45	27	0.09	0.98	0.98	0.05	0.08	226.15	276.28	0.000	0.090	M3 vs. M2	−0.41	0	0.01
M3. Piecewise	37.04	27	0.09	0.99	0.99	0.05	0.08	221.92	271.26	0.000	0.089	M3 vs. M1	−84.93*	−4	0.07
Study demands
M4. Intercept only	78.62	27	0.00	0.95	0.94	0.12	0.09	991.78	1041.91	0.087	0.147	M7 vs.M4	−37.13*	0	0.04
M5. Linear	85.14	31	0.00	0.94	0.95	0.11	0.09	990.30	1,028.63	0.083	0.140	M6 vs. M5	−35.84*	−4	0.03
M6. Quadratic	49.30	27	0.01	0.98	0.98	0.08	0.08	962.46	1,012.59	0.041	0.110	M7 vs. M6	−7.81	0	0
M7. Piecewise	41.49	27	0.05	0.99	0.98	0.06	0.08	954.65	1,004.79	0.016	0.097	M7 vs. M5	−43.65*	−4	0.03
Mental health
M8. Intercept only	47.71	27	0.01	0.97	0.97	0.07	0.09	1,411.09	1,461.22	0.037	0.107	M11 vs. M8	−11.96*	0	0.03
M9. Linear	38.31	31	0.17	0.99	0.99	0.04	0.06	1,389.98	1,428.31	0.000	0.079	M10 vs. M9	−10.10*	−4	0.00
M10. Quadratic	27.25	27	0.45	0.99	0.99	0.01	0.05	1,383.35	1,433.48	0.000	0.066	M11 vs. M10	−1.29	0	0.01
M11. Piecewise	25.96	27	0.52	1.00	1.00	0.00	0.05	1,382.16	1,432.29	0.000	0.063	M11 vs. M9	−11.75*	−4	0.01

χ², chi-square; df, degrees of freedom; TLI, Tucker–Lewis index; CFI, comparative fit index; RMSEA, root-mean-square error of approximation; SRMR, standardized root mean square residual; AIC, Akaike information criterion; BIC, Bayes information criterion; LL, lower level; UL, upper level; *statistically significant (p < 0.05); I, intercept; S1, linear slope; S2, quadratic slope or Piece 2 slope; Δχ², Satorra–Bentler scaled chi-square difference test. Underlined values = Best Fitting Model.