Table 3. Summary of direct medical cost*† per Lyme disease (LD) patient in Maryland Eastern Shore, 1997–2000.

Diagnosis group‡	Cohort	No. cases	Cost per case (US$)					Significance§
			Median	Mean	Minimum	Maximum	SD	1997	1998	1999	2000
Early-stage LD	1997	77	565	1,609	95	11,286	2,010	NA
	1998	63	337	869	78	9,720	1,542	S	NA
	1999	122	282	455	42	3,574	630	S	NS	NA
	2000	72	288	464	5	5,338	738	S	NS	NS	NA
Late-stage LD	1997	28	3,673	4,240	275	24,985	5,132	NA
	1998	24	654	1,472	125	6,417	1,839	S	NA
	1999	59	588	1,286	74	5,402	1,334	S	NS	NA
	2000	45	589	1,380	45	6,918	1,652	S	NS	NS	NA
Suspected LD	1997	153	169	326	45	9,564	948	NA
	1998	79	174	255	48	2,285	281	NS	NA
	1999	242	198	321	51	3,869	445	NS	NS	NA
	2000	244	238	361	42	7,816	601	NS	NS	NS	NA
Tick bite	1997	143	92	140	33	836	129	NA
	1998	55	93	227	34	3,432	502	S	NA
	1999	202	87	120	17	527	98	NS	S	NA
	2000	139	70	121	16	1,181	141	NS	S	NS	NA
Other	1997	490	196	319	8	6,236	495	NA
	1998	154	273	479	34	3,721	561	S	NA
	1999	573	215	321	36	5,091	435	NS	S	NA
	2000	451	256	381	17	4,157	452	NS	NS	NS	NA

*Direct medical costs were collected from medical record abstraction (1997–2000). Direct medical costs of LD included costs of physician visits, consultation, serologic testing, procedure, therapy, hospitalization/ER, and other relevant costs.
†All costs were converted to 2000 equivalent.
‡Patients were divided into 5 diagnosis groups: clinically defined early-stage LD, clinically defined late-stage LD, suspected LD, tick bite, and other related complaints.
§Differences between annual mean direct medical costs were analyzed by using 1-way analysis of variance followed by Bonferroni test; p<0.05; SD, standard deviation; NA, not available; S, significant; NS, not significant.