Breaking the chains? The effects of training a shelter dog in prison on criminal behavior and recidivism

Figures & data

Table 1. Participants’ functioning during incarceration and demographic characteristics.

	DCD (n = 121)		TAU (n = 120)
	M (SD; range)	n	M (SD; range)	n	F	d (95% CI)
Age (in years)^1	29.85 (11.79; 15.24–62.52)	121	32.54 (14.14; 14.90–73.19)	120	2.572
Incarceration functioning at baseline
Internalizing behavior problems	0.40 (0.41; 0.00–1.92)	121	0.42 (0.38; 0.00–1.61)	120	0.176	0.0506 (−0.202–0.3031)
Aggression	0.37 (0.32; 0.00–1.20)	121	0.30 (0.28; 0.00–1.35)	120	3.381	−0.2328 (−0.4861–0.0206)
Callous-unemotional traits	1.10 (0.36; 0.42–2.42)	97	1.06 (0.34; 0.29–2.00)	103	0.588	−0.1143 (−0.3919–0.1632)
Self-control	3.49 (0.60; 2.12–4.67)	97	3.63 (0.58; 2.00–5.00)	103	2.857	−0.2374 (−0.5157–0.0409)
Treatment motivation	2.04 (0.49; 1.09–3.00)	121	2.10 (0.48; 1.09–2.91)	120	0.643	−0.1237 (−0.3764–0.129)
Incarceration (in years)^2	1.24 (0.95; 0.20–5.07)	79	1.49 (1.46; 0.04–9.87)	76	1.555	−0.2038 (−0.5195–0.1119)
	%	n	%	n	χ^2
Gender					0.080	0.0364 (−0.2161–0.2890)
Female	5.8	7	6.7	8
Male	94.2	114	93.3	112
Cultural background					5.085*	0.2936 (0.0384 – 0.5488)
Native Dutch	60.3	73	45.8	55
1^st or 2^nd generation immigrant	39.7	48	54.2	65
Educational level					10.965*	0.4367 (0.1782 – 0.6951)
None or primary education	13.2	16	5.0	6
Secondary education	38.8	47	38.3	46
Tertiary education	31.4	38	47.5	57
Other or unknown	16.5	20	9.2	11
Type of offense^3					1.416	0.1538 (−0.0995 – 0.407)
(Attempted) homicide	12.4	15	10.8	13
Violent behavior	28.9	35	35.0	42
Theft or fraud	7.4	9	6.7	8
Sexual offenses	9.9	12	7.5	9
Drug-related crime	3.3	4	2.5	3
Other & unknown	38.0	46	37.5	45
Offense category					0.413	0.0829 (−0.1699 – 0.3356)
Single	22.3	27	25.8	31
Multiple	39.7	48	37.5	45
Unknown	38.0	46	36.7	44
Type of facility					.002	0.0058 (−0.2467 – 0.2583)
Youth	36.4	44	36.7	44
Adult	63.6	77	63.3	76
Treatment					2.503	0.2049 (−0.0489 – 0.4587)
Yes	50.7	76	61.7	74
No	15.7	19	22.5	27
Unknown	21.5	26	15.8	19

Note. DCD = Dutch Cell Dogs, TAU = treatment-as-usual, n = sample size, M = mean, SD= standard deviation, Age (in years)/Incarceration (in years) ¹ = reporting Welch statistics due to violation of homogeneity of variance, Incarceration (in years)² = incarceration length of current sentence (only available for a subset of sample), type of offense³ = some cells had expected count less than 5, therefore Fisher’s Exact test results are reported. Type of offense was determined on most severe crime, offense category = specifies how many of the sentences are based on a single or multiple offenses.

* p < 0.05.

Table 2. Recidivism results within 12-months post-release (N = 184).

	DCD (n = 95)		TAU (n = 89)
	%	n	%	n	χ^2	d (95% CI)
Recidivism					6.540*	−0.3839 (−0.6782–−0.0897)
At least one reconviction	39.9	38	22.5	20
No reconviction	60.0	57	77.5	69
Violent recidivism					0.837	−0.1348 (−0.4237–0.1540)
At least one violent offense	52.6	20	40.0	8
No violent offenses	47.4	18	60.0	12
	M (SD; range)	n	M (SD; range)	n	Wald χ^2
Number of offenses	1.37 (2.76; 0.00–16.00)	95	0.88 (2.19; 0.00–11.00)	89	1.579	−0.1959 (−0.4858–0.0.0939)
Number of violent offenses	1.30 (0.47; 1.00–2.00)	20	2.13 (2.03; 1.00–7.00)	8	2.482
					F
Time to first reconviction (days)	284 (172; 32–681)	38	271 (163; 8–547)	20	0.074	0.0769 (−0.4647–0.6186)

Note. DCD = Dutch Cell Dogs, TAU = treatment-as-usual, n = sample size, M = mean, SD = standard deviation,.

d = Cohen’s d effect size, 95% CI= 95% confidence interval.

* p < 0.05, **< p < 0.01, ***p < 0.001.

Figure 1. Survival curves for recidivism per study condition.

Note. DCD = Dutch Cell Dogs, TAU = treatment-as-usual.

Table 3. Recidivism over the whole follow-up period (N = 241).

	DCD (n = 121)		TAU (n = 120)
	M (SD; range)	n	M (SD; range)	n	HR (95% CI)
Program effects
Survival time to first reconviction (days)	775 (400.; 32–1610)	121	822 (325; 8–1606)	120	0.633 (0.387–1.036)

Note. DCD = Dutch Cell Dogs, TAU = treatment-as-usual, n = sample size, M = mean, SD= standard deviation, d = Cohen’s d effect size, 95% CI= 95% confidence interval.

Table 4. Self-reported criminal behavior at 6-months post program termination (N = 90).

	DCD (n = 43)		TAU (n = 47)
	M (SD; range)	n	M (SD; range)	n	Wald χ^2	d (95% CI)
Program effects
Self-reported delinquent behavior	1.56 (2.88; 0.00–12.00)	43	2.13 (4.06; 0.00–18.00)	47	0.538	0.1551 (−02593–0.5695)
Moderator effects						d (95% CI)
Age					6.595*	0.5624 (0.1332–0.9916)
Adolescents (</= 25-years-old)	2.46 (3.59; 0.00–12.00)	24	3.69 (5.99; 0.00–18.00)	13	0.444	0.2204 (−0.4279–0.8687)
Adults (> 25-years-old)	0.42 (0.69; 0.00–2.00)	19	1.53 (2.94; 0.00–11.00)	34	4.315*	0.6680 (0.0377–1.2982)
Callous-unemotional traits					6.912**	0.5768 (0.1468–1.0069)
Low CU	0.40 (1.00; 0.00–4.00)	20	1.83 (4.26; 0.00–18.00)	24	4.159*	0.6462 (0.0252–1.2672)
High CU	2.57 (3.57; 0.00–12.00)	23	2.44 (3.92; 0.00–12.00)	23	0.011	−0.0309 (−0.6090–0.5471)
Treatment motivation					4.125*	0.4384 (0.0153–0.8613)
Low motivation	2.84 (3.82; 0.00–12.00)	19	2.50 (4.88; 0.00–18.00)	22	0.052	−0.0713 (−0.6838–0.5413)
High motivation	0.54 (1.14; 0.00–4.00)	24	1.80 (3.25; 0.00–11.00)	25	3.983*	0.5949 (0.0107–1.1791)

Note. DCD = Dutch Cell Dogs, TAU = treatment-as-usual, n = sample size, M = mean, SD= standard deviation, d = Cohen’s d effect size, 95% CI= 95% confidence interval.

* p < 0.05, **< p < 0.01, ***p < 0.001.