Diabetic peripheral neuropathy: resource utilization and burden of illness

Figures & data

Figure 1. Algorithm for management of symptomatic DPN16. Reproduced from Lindsay TJ, et al. Treating diabetic peripheral neuropathic pain. American Family Physician 2010;82(2):151–158, with permission of the American Academy of Family Physicians.

Figure 2. Algorithm used to identify incident patients with DPN using LifeLink database.

Table 1. Characteristics of incident patients with DPN included in the analysis.

	Total
Number of patients	10,982
Male (%)	49.7
Mean age (years)	61.6
Group distribution (age in years)
18–44 (%)	8.7
45–64 (%)	54.7
65–80 (%)	27.9
80+ (%)	8.7
Patients treated* at baseline (%)	57.3
Patients treated* over 2-year -p (%)	68.0

*Treated refers to treatment with drugs analyzed for usage in Table 6.

Figure 3. Total cost ($) for different types of visits. ^Treatments only include pharmacy claims.

Table 2. Number and percentage of patients that make hospital, ER, and office visits.

	Pre-diagnosis period		Post-diagnosis period
	# patients	% patients	# patients	% patients	% Increase (post DPN diagnosis)	p-Value H0: Mpre = Mpost H1: Mpre < > Mpost
Hospital visits	3247	29.6%	3884	35.4%	19.6%	<0.001
ER visits	4548	41.4%	4920	44.8%	8.2%	<0.001
Office visits	10,871	99.0%	10,950	99.7%	0.7%	<0.001
Treatments*	10,330	94.1%	10,456	95.2%	1.2%	<0.001

*Treatments only include pharmacy claims.

H₀, Null Hypothesis, H₁, Alternative Hypothesis; M_pre, Percentage of patients that have a relevant claim pre-DPN diagnosis, M_post, Percentage of patients that have a relevant claim post-DPN diagnosis.

Table 3. Count, mean, median, and standard deviation of hospital, ER, and office visits.

	Pre-diagnosis period			Post-diagnosis period
	Total visits	Mean1^a	Mean2^a	Total visits	Mean1^a	Mean2^a	% Increase in visits/claims (post-DPN diagnosis)	p-value H0: M1pre = M1post H1: M1pre < > M1post	p-Value H0: M2pre = M2post H1: M2pre < > M2post
Hospital visits	5818	1.8	0.53	8470	2.2	0.77	45.6%	<0.001	<0.001
ER visits	10,285	2.3	0.94	12,373	2.5	1.13	20.3%	<0.001	<0.001
Office visits	262,614	24.2	23.91	325,945	29.8	29.68	24.1%	<0.001	<0.001
Treatments^b	502,499	48.6	45.76	602,685	57.6	54.88	19.9%	<0.001	<0.001

^aMean1 = Number of visits per patient with any relevant visit/claim; Mean2 = Number of visits per all patients.

^bTreatments only include pharmacy claims.

H₀, Null Hypothesis; H₁, Alternative Hypothesis; M1_pre, Mean1 pre-DPN diagnosis, M1_post, Mean1 post-DPN diagnosis; M2_pre, Mean2 pre-DPN diagnosis; M2_post, Mean2 post-DPN diagnosis.

Table 4. Cost per visit and annual cost per patient.

	Pre-diagnosis period		Post-diagnosis period
	Mean cost per visit	Annual cost per patient	Mean cost per visit	Annual cost per patient	% Increase (post DPN diagnosis)	p-value H0: Mpre = Mpost H1: Mpre < > Mpost	p-Value H0: ACpre = ACpost H1: ACpre < > ACpost
Hospital visits	17,677	15,837	19,302	21,046	9.2%	0.022	<0.001
ER visits	729	824	886	1114	21.5%	<0.001	<0.001
Office visits	91	1100	102	1513	11.6%	<0.001	<0.001
Treatments*	148	3606	161	4629	8.3%	0.004	<0.001

*Treatments only include pharmacy claims

H₀, Null Hypothesis, H₁, Alternative Hypothesis; M_pre, Mean cost per visit in pre-DPN diagnosis, M_post, Mean cost per visit in post-DPN diagnosis; AC_pre, Annual cost per patient with relevant visit in pre-DPN diagnosis, AC_post, Annual cost per patient with relevant visit in post-DPN diagnosis.

Table 5. Number and pecentage of patients suffering from co-morbidities.

	Pre-diagnosis period		Post-diagnosis period
	# Patients	% of all patients^a	# Patients	% of all patients	% increase in # of patients (post-DPN diagnosis)	p-Value H0: Ppre = Ppost H1: Ppre < > Ppost
Post-herpetic neuralgia	234	2.1%	251	2.3%	7.3%	0.42
Cancer	1158	10.5%	1318	12.0%	13.8%	<0.001
Osteoarthritis	3170	28.9%	3679	33.5%	16.1%	<0.001
Back & neck pain	2487	22.6%	2765	25.2%	11.2%	<0.001
Low back pain with neuropathic component	3194	29.1%	3509	32.0%	9.9%	<0.001
Other pain co-morbidities^b	1639	14.9%	2246	20.5%	37.0%	<0.001
Other diabetic complications^c	5475	49.9%	6528	59.4%	19.2%	<0.001
Depression	1355	12.3%	1671	15.2%	23.3%	<0.001
Sleep disorder	1883	17.1%	1946	17.7%	3.3%	0.26
Total^d	9079		9620		6.0%	<0.001

^a% for any co-morbidity is calculated by number of patients suffering from the co-morbidity/total no. of patients (10,982).

^bOther pain co-morbidities include atypical facial pain, phantom limb pain, trigeminal neuralgia, reflex sympathetic dystrophy, nerve root and plexus disorders, other disorders of soft tissues, and inflammatory and toxic neuropathy.

^cOther diabetic complications include diabetic retinopathy/cataracts, nephropathy/Dialysis/renal failure/ESRD, peripheral vascular disease, gangrene/diabetic foot/diabetic foot ulcer and other diabetic complications.

^dTotal no. of patients suffering from any of the above-mentioned co-morbidities.

H₀, Null Hypothesis, H₁, Alternative Hypothesis; P_pre, Proportion of patients suffering from a co-morbidity pre-DPN diagnosis, P_post, Proportion of patients suffering from a co-morbidity post-DPN diagnosis.

Table 6. Drug/class usage by number of patients, percentage of patients, and percentage of class possession days.

	Pre-diagnosis period		Post-diagnosis period
Drug/class usage	# of patients	% of patients^a	% of class possession days^b	# of patients	% of patients^a	% of class possession days^b	% Increase in number of patients (post-DPN diagnosis)	p-value H0: Ppre = Ppost H1: Ppre < > Ppost	p-Value H0: CPDpre = CPDpost H1: CPDpre < > CPDpost
Gabapentin	1267	12%	0.34	1977	18%	0.40	56%	<0.001	<0.001
Pregabalin	782	7%	0.27	921	8%	0.37	18%	<0.001	<0.001
Other ACONs	697	6%	0.48	847	8%	0.50	22%	<0.001	0.43
Duloxetin HCL	457	4%	0.44	621	6%	0.48	36%	<0.001	0.21
Other ADEPs	2684	24%	0.59	2941	27%	0.64	10%	<0.001	<0.001
NSAID	3393	31%	0.22	3263	30%	0.23	4%	0.06	0.07
ODPN	2125	19%	0.28	2441	22%	0.31	15%	<0.001	0.008
OP2L	286	3%	0.43	393	4%	0.43	37%	<0.001	0.78
OP2S	1569	14%	0.12	1983	18%	0.14	26%	<0.001	0.04
OP34	4784	44%	0.14	5057	46%	0.17	6%	<0.001	<0.001

^a% of patients is calculated out of total patients (10,982).

^b% class possession days = Sum of days supply for patients that have used this drug-class out of a total of 730 days of potential drug class usage

H₀, Null Hypothesis; H₁, Alternative Hypothesis; P_pre, Proportion of patients taking a drug/class pre-DPN diagnosis, P_post, Proportion of patients taking a drug/class post-DPN diagnosis; CPD_pre, Percentage of class possession days of a drug/class, pre-DPN diagnosis; CPD_post, Percentage of class possession days of a drug/class, post-DPN diagnosis.

ACON, Anticonvulsants; ADEP, Antidepressants; ODPN, Drugs, other than those belonging to the specified classes, typically used for DPN patients (e.g., anti-arrhythmics, benzodiazepines, lidocaine); NSAID, Nonsteroidal Anti-inflammatory Drugs; OP2S, Opioid Schedule 2 Short-Acting; OP2L, Opioid Schedule 2 Long-Acting; OP34, Opioid Schedule ¾.

Lindsay TJ, Rodgers BC, Savath V, Hettinger K. Treating diabetic peripheral neuropathic pain. Am Fam physician 2010;82:151-8

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