Factors associated with opioid overdose: a 10-year retrospective study of patients in a large integrated health care system

Figures & data

Figure 1 ODs in Geisinger service area.

Abbreviations: GHS, Geisinger Health System; OD, opioid overdose.

Table 1 Study demographic and outcome variables among patients with one or more ODs (N=2,039)

Demographic variables	Patients, n (%)	95% CI
Age groups (years)
10–17	41 (2.01)	1.48–2.72
18–35	530 (25.99)	24.13–27.94
36–55	630 (30.90)	28.93–32.94
56–64	242 (12.87)	10.53–13.35
65–95	596 (29.23)	27.29–31.24
Sex
Male	944 (46.34)	44.18–48.52
Female	1,093 (53.66)	51.48–55.82
Race
White	1,961 (96.17)	95.25–96.93
Non-white	78 (3.83)	3.07–4.75
Marital status
Married	736 (36.10)	34.04–38.21
Not married	1,303 (63.90)	61.79–65.96
Employment status
Employed	449 (22.02)	20.27–23.87
Not employed	1,590 (77.98)	76.13–79.73
Private/commercial insurance
Yes	1,071 (52.53)	50.35–54.69
No	968 (47.47)	45.31–49.65
Geisinger PCP
Yes	1,767 (86.66)	85.11–88.07
No	272 (13.34)	11.93–14.89
Has three or more chronic diseases
Yes	356 (17.46)	15.87–19.17
No	1,683 (82.54)	80.83–84.13
Charlson chronic disease score 4+
Yes	749 (36.73)	34.67–38.85
No	1,290 (63.27)	61.15–65.33
Any mental disorder pre-OD
Yes	723 (35.46)	33.41–37.56
No	1,316 (64.54)	62.44–66.59
Index OD event: heroin or methadone
Yes	420 (20.60)	18.90–22.41
No	1,619 (79.40)	77.59–81.10
Outcome variables
Inpatient admissions 1 year post-OD
Yes	581 (28.49)	26.57–30.50
No	1,458 (71.51)	69.50–73.43
Emergency department visits 1 year post-OD
Yes	656 (32.17)	30.18–34.23
No	1,383 (67.83)	65.77–69.82
High number of outpatient visits (75th percentile) 1 year post-OD
Yes	546 (26.78)	24.90–28.74
No	1,493 (73.22)	71.26–75.10
High total costs (75th percentile) 1 year post-OD
Yes	509 (24.96)	23.13–26.89
No	1,530 (75.04)	73.11–76.87
Two or more ODs
Yes	96 (4.71)	3.87–5.72
No	1,943 (95.29)	94.28–96.13
Naloxone Rx order 1 year post-ODa
Yes	191 (9.37)	8.18–10.71
No	1,848 (90.63)	89.29–91.82
Died within 1 year post-OD
Yes	191 (9.37)	8.18–10.71
No	1,848 (90.63)	89.29–91.82

Notes: All patients had one or more ICD-9-coded ODs during the study period (age range: 10–95 years).

a Naloxone Rx order 1 year pre-OD =17.3 (95% CI =15.7–19.0).

Abbreviations: CI, confidence interval; ICD-9, International Classification of Diseases-9; OD, opioid overdose; PCP, primary care physician; Rx, prescription.

Figure 2 Study age distribution among patients with one or more ODs.

Abbreviation: OD, opioid overdose.

Table 2 Significant bivariate results (P<0.01) for patient deaths within 1 year post-OD among patients with one or more ODs (N=2,039)

Variables	Patients, n (%)	Dead (%)	95% CI	Alive (%)	95% CI	P-value
Age groupsa (years)						<0.001
10–35	571 (28.00)	1.75	0.94–3.23	98.25	96.77–99.06
36–55	630 (30.90)	6.51	4.83–8.72	93.49	91.28–95.17
56–64	242 (11.87)	12.81	9.15–17.65	87.19	82.35–90.85
65–95	596 (29.23)	18.29	15.38–21.60	81.71	78.40–84.62
Sex						0.0038
Male	944 (46.2)	11.33	9.46–13.52	88.67	86.48–90.54
Female	1,093 (53.8)	7.59	6.16–9.32	92.41	90.68–93.84
Marital status						0.0009
Married	736 (36.10)	12.23	10.05–14.8	87.77	85.2–89.95
Not married	1,303 (63.90)	7.75	6.42–9.34	92.25	90.66–93.58
Employment status						<0.001
Employed	449 (22.02)	3.79	2.37–6.01	96.21	93.99–97.63
Not employed	1,590 (77.98)	10.94	9.50–12.58	89.06	87.42–90.5
CVD pre-OD						<0.001
Yes	451 (22.10)	20.18	16.72–24.14	79.82	75.86–83.28
No	1,588 (77.9)	6.30	5.20–7.60	93.70	92.4–94.8
Hypertension pre-OD						<0.001
Yes	553 (27.12)	17.18	14.26–20.56	82.82	79.44–85.74
No	1,486 (72.88)	6.46	5.32–7.83	93.54	92.17–94.68
Chronic kidney disease pre-OD						<0.001
Yes	145 (7.11)	24.83	18.47–32.5	75.17	67.5–81.53
No	1,894 (92.89)	8.18	7.03–9.51	91.82	90.49–92.97
Diabetes pre-OD						<0.001
Yes	280 (13.73)	22.14	17.66–27.39	77.86	72.61–82.34
No	1,759 (86.27)	7.33	6.20–8.65	92.67	91.35–93.8
COPD pre-OD						<0.001
Yes	162 (7.95)	23.46	17.56–30.6	76.54	69.4–82.44
No	1,877 (92.05)	8.15	7.00–9.48	91.85	90.52–93.00
Cancer pre-OD						<0.001
Yes	261 (12.80)	34.48	28.96–40.46	65.52	59.54–71.04
No	1,778 (87.20)	5.68	4.70–6.86	94.32	93.14–95.31
Opioid Rx order pre-ODb						<0.001
None	662 (32.47)	5.44	3.95–7.45	94.56	92.55–96.05
1–2 orders	648 (31.78)	5.86	4.30–7.96	94.14	92.04–95.71
3–8 orders	413 (20.26)	12.59	9.72–16.16	87.41	83.84–90.28
9+ orders	316 (15.50)	20.57	16.46–25.39	79.43	74.61–83.54
Antianxiety Rx order pre-OD						<0.001
Yes	735 (36.05)	13.20	10.93–15.84	86.80	84.16–89.07
No	1,304 (63.95)	7.21	5.92–8.75	92.79	91.25–94.08
Hypnotic Rx order pre-OD						0.0061
Yes	564 (27.66)	12.23	9.78–15.21	87.77	84.79–90.23
No	1,475 (72.34)	8.27	6.97–9.79	91.73	90.21–93.03
Migraine Rx order pre-OD						<0.001
Yes	944 (46.30)	12.61	10.63–14.88	87.39	85.12–89.37
No	1,095 (53.70)	6.58	5.25–8.21	93.42	91.79–94.75
Antipsychotic Rx order pre-OD						<0.001
Yes	406 (19.91)	15.27	12.09–19.11	84.73	80.89–87.91
No	1,633 (80.09)	7.90	6.69–9.31	92.10	90.69–93.31
Muscle Rx relaxant order pre-OD						0.0099
Yes	388 (19.03)	5.93	3.97–8.77	94.07	91.24–96.03
No	1,651 (80.97)	10.18	8.81–11.73	89.82	88.27–91.19
Benzodiazepine Rx order pre-OD						<0.001
Yes	670 (32.86)	13.88	11.46–16.71	86.12	83.29–88.54
No	1,369 (67.14)	7.16	5.91–8.65	92.84	91.35–94.09

Notes: All patients had one or more ICD-9-coded ODs during the study period (age range: 10–95 years).

a Since no deaths occurred among the age group of 10–17 years, this group was collapsed into the age group of 18–35 years.

b Opioid Rx orders 1 year post-OD: none =30.0%; 1–2 Rx orders =23.7%; 3–8 Rx orders =30.2%; nine or more Rx orders =16.1%.

Abbreviations: CI, confidence interval; COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; ICD-9, International Classification of Diseases-9; OD, opioid overdose; OR, odds ratio; Rx, prescription.

Table 3 Significant multiple logistic regression results (P<0.01) for patient deaths 1 year post-OD among patients with one or more ODs (N=2,039)

Variablesa	OR	95% CI	P-value
Mental health disorder pre-OD	0.55	0.35–0.86	0.008
Cancer pre-OD	4.22	2.83–6.30	<0.001
Geisinger PCP pre-OD	0.48	0.29–0.80	0.005
Benzodiazepine Rx order pre-OD	1.76	1.19–2.60	0.004
Diabetes pre-OD	2.18	1.44–3.31	<0.001
Commercial/private insurance pre-OD	0.52	0.36–0.75	0.001
Substance use disorders pre-OD	2.85	1.42–5.76	0.003
Muscle relaxant Rx pre-OD	0.39	0.23–0.66	<0.001
Opioid Rx orders 9+ pre-OD vs none	2.29	1.48–3.54	<0.001
Charlson chronic disease score 4+ pre-OD	2.31	1.27–4.22	0.006

Notes: Area under the ROC curve =0.85; Hosmer–Lemeshow test = P>0.99. Results shown are for significant variables that were retained in the final model with a P-value of <0.01. All patients had one or more ICD-9-coded ODs during the study period (age range: 10–95 years).

a Age (in years) and male sex were also included in the logistic regression, resulting in an adjusted age OR =1.01, P=0.036, and an adjusted male sex OR =1.56, P=0.014, in the final stepwise model.

Abbreviations: CI, confidence interval; ICD-9, International Classification of Diseases-9; OD, opioid overdose; OR, odds ratio; PCP, primary care physician; ROC, receiver operating characteristic.

Table 4 Significant multiple logistic regression results (P<0.01) for multiple OD events among patients with one or more OD (N=2,039)

Variablesa	OR	95% CI	P-value
Anticonvulsant Rx order pre-OD	1.96	1.23–3.14	0.005
CVD pre-OD	0.28	0.12–0.69	0.006
Buprenorphine Rx order pre-OD	12.30	5.92–25.53	<0.001
Migraine Rx orders pre-OD	0.46	0.28–0.75	0.002

Notes: Area under the ROC curve =0.71; Hosmer–Lemeshow test = P>0.71. Results shown are for the significant variables that were retained in the final model with a P-value of <0.01. All patients had one or more ICD-9-coded ODs during the study period (age range: 10–95 years).

a Age (in years) and male sex were also included in the logistic regression, resulting in an adjusted age OR =1.00, P=0.230, and an adjusted male sex OR =1.40, P=0.136, in the final stepwise model.

Abbreviations: CI, confidence interval; CVD, cardiovascular disease; ICD-9, International Classification of Diseases-9; OD, opioid overdose; OR, odds ratio; ROC, receiver operating characteristic; Rx, prescription.

Table 5 Significant multiple logistic regression results (P<0.01) for high number of outpatient visits (75th percentile) 1 year post-OD among patients with one or more ODs (N=2,039)

Variablesa	OR	95% CI	P-value
Mental health disorder pre-OD	1.52	1.20–1.92	<0.001
Geisinger PCP pre-OD	1.97	1.29–3.02	0.002
CVD pre-OD	1.62	1.23–2.12	0.001
Commercial/private insurance pre-OD	1.74	1.39–2.19	<0.001
Opioid Rx orders 1–2 pre-OD vs none	2.32	1.68–3.20	<0.001
Opioid Rx orders 3–8 pre-OD vs none	3.33	2.36–4.72	<0.001
Opioid Rx orders 9+ pre-OD vs none	4.62	3.20–6.68	<0.001
Cancer pre-OD	1.70	1.26–2.30	<0.001

Notes: Area under the ROC curve =0.74; Hosmer–Lemeshow test = P>0.79. Results shown are for significant variables that were retained in the final model with a P-value of <0.01. All patients had one or more ICD-9-coded ODs during the study period.

a Age (in years) and male sex were also included in the logistic regression model, resulting in an adjusted age OR =1.01, P=0.004, and an adjusted male sex OR =0.76, P=0.017, in the final stepwise model.

Abbreviations: CI, confidence interval; CVD, cardiovascular disease; ICD-9, International Classification of Diseases-9; OD, opioid overdose; OR, odds ratio; PCP, primary care physician; ROC, receiver operating characteristic; Rx, prescription.

Table 6 Significant multiple logistic regression results (P<0.01) for high total costs (75th percentile) 1 year post-OD among patients with one or more ODs (N=2,039)

Variablesa	OR	95% CI	P-value
Geisinger PCP pre-OD	1.97	1.26–3.08	0.003
Opioid Rx orders 1–2 pre-OD vs none	2.06	1.44–2.97	<0.001
Opioid Rx orders 3–8 pre-OD vs none	3.14	2.12–4.65	<0.001
Opioid Rx orders 9+ pre-OD vs none	4.62	3.04–7.01	<0.001
Charlson chronic disease score 4+ pre-OD	2.57	1.83–3.61	<0.001
Migraine Rx order pre-OD	1.48	1.14–1.92	0.003
Antianxiety Rx order pre-OD	1.44	1.13–1.85	0.004
CVD pre-OD	2.15	1.63–2.86	<0.001

Notes: Area under the ROC curve =0.78; Hosmer–Lemeshow test = P>0.393. Results shown are for significant variables that were retained in the final model with a P-value of <0.01. All patients had one or more ICD-9-coded ODs during the study period.

a Age (in years) and male sex were also included in the logistic regression model, resulting in age OR =0.99, P=0.023, and male sex OR =0.92, P=0.92, in the final stepwise model.

Abbreviations: CI, confidence interval; CVD, cardiovascular disease; ICD-9, International Classification of Diseases-9; OD, opioid overdose; OR, odds ratio; PCP, primary care physician; ROC, receiver operating characteristic; Rx, prescription.