The burden of chronic low back pain with and without a neuropathic component: a healthcare resource use and cost analysis

Figures & data

Figure 1.  Classification of CLBP patients. Dx, diagnosis; Rx, treatment; LBP, low back pain; ICD-9, International Statistical Classification of Diseases, Ninth Revision; CLBP, chronic low back pain.

Table 1.  Patient demographics of CLBP patients at the index event.

	All CLBP patients	CLBP patients woNP	CLBP patients wNP	p-value^a
Number of patients	39,425	3784	35,641
Proportion of total (%)		9.6	90.4
Male (%)	36.2	38.3	36.0	0.02^b
Mean age (years)	51.0	50.3	51.0	<0.0001^b
Prior opioid use (%)	70.3	56.3	71.8	<0.0001^b
Cancer diagnosis (%)	7.0	6.8	7.0	NS^b
Psychiatric comorbid diagnosis of depression (ICD-9 = 296, 300 or 301) (%)	7.7	3.2	8.1	<0.001^b
Patients on prescription medication at baseline (%)	73.9	61.8	75.2	<0.0001^b
NSAID monotherapy	7.9	11.0	7.6	<0.0001^c
Any AD/AED	31.4	42.0	30.4	<0.0001^c
Schedules III and IV drugs^d	37.3	34.1	37.6	<0.0009^c
Schedule II drugs^d	23.5	12.9	24.4	<0.0001^c

^aCLBP patients woNP vs CLBP patients wNP; ^bt-test; ^cχ²-test; ^dAccording to US Drug Enforcement Agency drug schedules.

CLBP, chronic low back pain; woNP, without a neuropathic component; wNP, with a neuropathic component; NS, not significant; ICD-9, International Statistical Classification of Diseases, Ninth Revision; NSAID, non-steroidal anti-inflammatory drug; AD, antidepressants; AED, anti-epileptic drugs.

Table 2.  Treatment exposure during 12-month follow-up period by CLBP patients according to pain type.

	CLBP patients woNP		CLBP patients wNP		p-value^a,b
	Patients (%)	Mean number of months exposed/patient	Patients (%)	Mean number of months exposed/patient
NSAID monotherapy	12.6	3.9	10.3	3.9	NS
Any AD/AED (including with or without NSAIDs)	24.5	7.2	23.2	6.7	<0.0001
Schedules III and IV drugs^c (including with or without NSAIDs or any AD/AEDs)	30.2	4.9	32.8	5.9	<0.0001
Schedule II drugs^c (including with or without NSAIDs or any AD/AEDs or schedules III and IV drugs)	11.7	4.5	20.1	6.3	<0.0001
Not on prescription medication	21.0	5.5	13.6	4.3	<0.0001

^aCLBP patients woNP vs and CLBP patients wNP; ^bχ²-test, based on the PROC GLM controlling for sex, age, and diagnosis of depression

(ICD-9); ^cAccording to US Drug Enforcement Agency drug schedules.

CLBP, chronic low back pain; woNP, without a neuropathic component; wNP, with a neuropathic component; NSAID, non-steroidal anti-inflammatory drug; NS, not significant; AD, antidepressant; AED, anti-epileptic drug; ICD-9, International Statistical Classification of Diseases, Ninth Revision.

Table 3.  Comparison of resource use for CLBP patients according to pain type during 12-month follow-up period.

Resource	CLBP patients woNP (%)	CLBP patients wNP (%)	p-value^a,b
LBP diagnostic tests	7.1	24.3	<0.0001
LBP ER visit	4.9	9.3	<0.0001
LBP hospital visits	1.0	5.1	<0.0001
LBP minimally invasive procedure	6.1	18.3	<0.0001
LBP major procedure	1.1	5.7	<0.0001
LBP physiotherapy	43.0	42.8	NS

^aCLBP patients woNP vs CLBP patients wNP; ^bχ²-test.

CLBP, chronic low back pain; woNP, without a neuropathic component; wNP, with a neuropathic component; LBP, low back pain; ER, emergency room; NS, not significant.

Figure 2.  Comparison of proportions of average annual cost of resource use per patient for CLBP patients according to pain type during 12-month follow-up period. ^aAverage annual cost of resource use per patient (p < 0.0001, CLBP patients woNP vs CLBP patients wNP). CLBP, chronic low back pain; woNP, without a neuropathic component; wNP, with a neuropathic component; LBP, low back pain; ER, emergency room.