Price of pain: population-based cohort burden of disease analysis of medication cost of herpes zoster and postherpetic neuralgia

Figures & data

Table 1 Total cost and cost per episode of treating herpes zoster-related pain by year

	Herpes zoster episodes				Herpes zoster with PHN
Year	Episodes	Rxs	Total cost	Mean cost (95% CI)	Episodes	Rxs	Total cost	Mean PHN cost (95% CI)
1997/1998	3,844	6,082	$121,438	$31.59 ($25.35, $37.84)	331	3,925	$96,555	$291.71 ($225.45, $357.96)
1998/1999	3,781	6,309	$130,276	$34.46 ($28.38, $40.53)	349	4,229	$107,007	$306.61 ($248.06, $365.16)
1999/2000	3,941	7,820	$245,329	$62.25 ($50.74, $73.76)	367	5,526	$215,149	$586.24 ($475.95, $696.53)
2000/2001	3,954	7,629	$224,626	$56.81 ($46.70, $66.92)	399	5,440	$192,830	$483.28 ($393.34, $573.23)
2001/2002	4,060	8,282	$271,792	$66.94 ($52.67, $81.22)	429	6,064	$236,570	$551.45 ($425.20, $677.69)
2002/2003	4,126	8,015	$254,967	$61.80 ($52.07, $71.52)	410	5,554	$215,795	$526.33 ($440.91, $611.75)
2003/2004	4,070	7,783	$231,833	$56.96 ($47.57, $66.35)	375	5,541	$191,562	$510.83 ($421.55, $600.12)
2004/2005	4,087	7,070	$194,372	$47.56 ($40.78, $54.34)	379	4,670	$153,891	$406.05 ($343.97, $468.12)
2005/2006	4,131	7,886	$214,436	$51.91 ($44.30, $59.51)	432	5,581	$172,052	$398.27 ($334.80, $461.74)
2006/2007	4,143	7,918	$207,393	$50.06 ($42.52, $57.60)	377	5,586	$165,257	$438.35 ($366.84, $509.86)
2007/2008	4,207	7,968	$193,942	$46.10 ($39.89, $52.31)	377	5,674	$152,928	$405.64 ($348.23, $463.06)
2008/2009	4,295	9,435	$252,994	$58.90 ($50.77, $67.04)	440	7,147	$209,013	$475.03 ($407.32, $542.74)
2009/2010	4,584	9,393	$267,865	$58.43 ($49.20, $67.67)	427	7,024	$222,968	$522.17 ($434.64, $609.71)
2010/2011	4,622	9,102	$276,383	$59.80 ($49.42, $70.17)	449	6,617	$230,827	$514.09 ($416.88, $611.30)
2011/2012	4,984	11,065	$332,981	$66.81 ($56.84, $76.78)	497	8,398	$281,342	$566.08 ($477.51, $654.66)

Notes: Costs include all prescriptions from date of diagnosis to end of episode and include prescriptions for postherpetic neuralgia when present. The herpes zoster with PHN group includes only those cases of herpes zoster that converted to neuralgia and includes prescriptions from the start of the herpes zoster episode. Costs are reported in 2013 Canadian dollars.

Abbreviations: PHN, postherpetic neuralgia; Rxs, prescriptions; CI, confidence interval.

Figure 1 Mean cost per episode of herpes zoster-associated pain treatment by age at diagnosis. Costs adjusted for inflation to 2013 Canadian dollars.

Figure 2 Treatment of postherpetic neuralgia episodes by drug class.

Notes: Numbers of episodes treated by drug class. A single episode can be treated with more than one class of drug, thus a single episode can contribute data to more than one category.
Abbreviation: NSAID, nonsteroidal anti-inflammatory drug.

Figure 3 Distribution of days of drug treatment per episode by class.

Notes: Boxplot of the number of days of drug treatment per episode by drug class for herpes zoster with postherpetic neuralgia. ◊ = mean.
Abbreviation: NSAID, nonsteroidal anti-inflammatory drug.

Table 2 Treatment of herpes zoster-related pain by drug class

	Antidepressants		Anticonvulsants		NSAIDs		Opioids		Miscellaneous
Year	Users	Cost (CAD)	Users	Cost (CAD)	Users	Cost (CAD)	Users	Cost (CAD)	Users	Cost (CAD)
1997	348	$35,607	153	$15,520	400	$23,122	866	$33,208	544	$13,980
1998	378	$29,458	168	$29,124	380	$34,326	838	$23,896	520	$13,471
1999	404	$39,612	235	$83,398	475	$64,916	893	$43,752	571	$13,651
2000	424	$46,315	250	$64,642	479	$66,661	893	$34,441	505	$12,567
2001	440	$48,663	293	$85,722	469	$47,112	885	$70,139	544	$20,157
2002	435	$52,683	298	$82,635	453	$48,795	920	$56,048	574	$14,806
2003	425	$46,661	303	$71,625	398	$32,101	819	$62,947	532	$18,498
2004	444	$49,589	326	$63,383	368	$28,335	889	$36,793	552	$16,273
2005	445	$44,140	364	$78,247	377	$29,826	902	$40,096	540	$22,127
2006	419	$49,873	389	$70,737	364	$27,909	848	$31,437	502	$27,437
2007	396	$37,136	485	$86,579	325	$24,099	829	$31,008	501	$15,119
2008	397	$51,837	533	$112,910	389	$27,118	828	$35,141	515	$25,988
2009	430	$54,128	540	$122,855	348	$24,299	866	$41,026	518	$25,558
2010	428	$49,949	581	$123,577	326	$23,549	853	$42,545	526	$36,763
2011	447	$67,903	694	$132,685	383	$31,252	926	$55,318	582	$45,824

Notes: Total treated herpes zoster episodes (users) and drug class cost by year. Numbers are for all herpes zoster-related pain, including postherpetic neuralgia. A single episode can be treated with more than one class of drug, possibly contributing data to multiple categories. Costs adjusted for inflation to 2013 Canadian dollars.

Abbreviation: NSAID, nonsteroidal anti-inflammatory drug.