Validity of Major Osteoporotic Fracture Diagnoses in the Danish National Patient Registry

Figures & data

Table 1 NPR Coding of MOF Diagnoses, Imaging Studies and Surgical Procedures for MOF Fracture Sites

Fracture Site	Diagnoses (ICD-10)	Imaging Studies	Surgical Procedures
Hip fracture	S720*, S721*, S722*	UXRG10*, UXRG15*, UXMG10*, UXMG15*, UXCG10*, UXCG15*	KNFB*, KNFJ4*-9*
Humerus fracture
Fracture of humerus (proximal)	S422*, S423*	UXRF15*, UXRF20*, UXCF15*, UXCF20*
Clinical vertebral fracture
Fracture of lumbar spine (lumbar VF)	S320*	UXRE30*, UXCE30*
Fracture of spine, unspecified level	DT08*
Fracture of thoracic spine (thoracic VF)	S220*, S221*	UXRE20*, UXCE20*
Fracture of cervical vertebraes	S120*, S121*, S122*	UXRE10*, UXCE10*
Wrist fracture
Fracture of forearm (distal)	S525*, S526*	UXRF30*, UXRF40*, UXRF45*, UXMF45*

Note: *Substring characters were included eg DS721A, DS721B etc.

Abbreviations: NPR, National Patient Registry; MOF, Major Osteoporotic Fracture.

Table 2 Study Population Characteristics and PPVs in Random NPR Data Extraction of ICD-10 Coded MOFs Verified Though Medical Record Review

Diagnoses	Total, N (%)	Female, N (%)	Age on Date of Fracture, Median (Q1;Q3)	Verified ICD-10 Through Medical Record Review, N/ Total, N
MOF	2400	1697 (71)	73 (64;83)	2375/2400
PPV (95% CI)				0.99 (0.98;0.99)
Hip Fracture	600	405 (68)	82 (73;89)	596/600
PPV (95% CI)				0.99 (0.98;1.00)
Humerus fracture	600	457 (76)	72 (63;79)	594/600
PPV (95% CI)				0.99 (0.98;1.00)
Clinical vertebral fracture	600	349 (58)	73 (62;81)	592/600
PPV (95% CI)				0.99 (0.97;0.99)
Wrist fracture	600	486 (81)	70 (61;78)	593/600
PPV (95% CI)				0.99 (0.98;1.00)

Abbreviations: PPV, Positive Predictive Value; MOFs, Major Osteoporotic Fractures.

Table 3 PPVs of ICD-10 Coded MOF Diagnoses Verified in Medical Records on Same Date with Imaging Studies and Surgical Procedures Within + 7 Days in the NPR by All Diagnoses, by Diagnoses Where the Admission Date* is the 1st in the NPR and by Diagnoses Where the Admission Date is the ≥2nd in the NPR

Diagnoses	Total ICD-10	Verified on Same Date, N/N Total	Imaging Studies in the NPR (+7 Days), N/N Total	Surgical Codes in the NPR (+7 Days), N/N Total	Surgical Codes and Imaging Studies in the NPR (+ 7 Days), N/N Total
All	N=2400	N=1332/2400
PPV (95% CI)		0.55 (0.53;0.58)
Hip Fracture	600	416/600	413/517	386/505	385/463
PPV (95% CI)		0.69 (0.65;0.73)	0.80 (0.76;0.83)	0.76 (0.72;0.80)	0.83 (0.79;0.86)
Humerus fracture	600	285/600	279/515	NA	NA
PPV (95% CI)		0.47 (0.43;0.52)	0.54 (0.50;0.59)	NA	NA
Clinical vertebral fracture	600	284/600	196/295	NA	NA
PPV (95% CI)		0.47 (0.43;0.51)	0.66 (0.61;0.72)	NA	NA
Wrist fracture	600	347/600	340/474	NA	NA
PPV (95% CI)		0.58 (0.54;0.62)	0.72 (0.67;0.76)	NA	NA
1st NPR admission date	N=1733	N=1266/1733
PPV (95% CI)		0.73 (0.71;0.75)
Hip Fracture	474	392/474	390/446	365/434	365/415
PPV (95% CI)		0.83 (0.79;0.86)	0.87 (0.84;0.90)	0.84 (0.80;0.87)	0.88 (0.84;0.91)
Humerus fracture	376	276/376	271/346	NA	NA
PPV (95% CI)		0.73 (0.69;0.78)	0.78 (0.74;0.83)	NA	NA
Clinical vertebral fracture	460	264/460	189/241	NA	NA
PPV (95% CI)		0.57 (0.53;0.62)	0.78 (0.73;0.83)	NA	NA
Wrist fracture	423	334/423	328/377	NA	NA
PPV (95% CI)		0.79 (0.75;0.83)	0.87 (0.83;0.90)	NA	NA
≥2nd NPR admission date	N=667	N=66/667
PPV (95% CI)		0.10 (0.08;0.12)
Hip Fracture	126	24/126	23/71	21/71	20/48
PPV (95% CI)		0.19 (0.13;0.27)	0.32 (0.22;0.45)	0.30 (0.19;0.42)	0.42 (0.28;0.57)
Humerus fracture	224	9/224	8/169	NA	NA
PPV (95% CI)		0.04 (0.02;0.07)	0.05 (0.02;0.09)	NA	NA
Clinical vertebral fracture	140	20/140	7/54	NA	NA
PPV (95% CI)		0.14 (0.09;0.21)	0.13 (0.05;0.25)	NA	NA
Wrist fracture	177	13/177	12/97	NA	NA
PPV (95% CI)		0.07 (0.04;0.12)	0.12 (0.07;0.21)	NA	NA

Notes: *Admission date is the date the patient is admitted to the hospital for an inpatient contact and respectively, the date of visit for an outpatient contact.

Abbreviations: PPV, Positive Predictive Value; MOFs, Major Osteoporotic Fractures; NA, Not applicable as surgical procedures were only investigated for hip fractures.

Figure 1 Flowchart of analysis approach.

Table 4 PPVs of ≥2nd Admission Date* in the NPR with Grace Periods of 0, 30, 60, 90 and 180 Days

Diagnoses	Total ICD-10, N=667	Verified on Same Date, N/ N Total	Verified on Same Date, N / N with ≥ 30 Days Between 1st and ≥2nd Admission Date in NPR	Verified on Same Date, N / N with ≥ 60 Days Between 1st and ≥2nd Admission Date in NPR	Verified on Same Date, N / N with ≥ 90 Days Between 1st and ≥2nd Admission Date in NPR	Verified on Same Date, N / N with ≥ 180 Days Between 1st and ≥2nd Admission Date in NPR
Hip Fracture	126	24/126	13/38	13/29	13/24	7/12
PPV (95% CI)		0.19 (0.13;0.27)	0.34 (0.20;0.51)	0.45 (0.26;0.64)	0.54 (0.33;0.74)	0.58 (0.28;0.85)
Humerus fracture	224	9/224	5/39	NR	NR	NR
PPV (95% CI)		0.04 (0.02;0.07)	0.13 (0.04;0.27)	0.17 (0.05;0.37)	0.20 (0.06;0.44)	0.30 (0.07;0.65)
Clinical vertebral fracture	140	20/140	8/65	7/44	6/36	NR
PPV (95% CI)		0.14 (0.09;0.21)	0.12 (0.05;0.23)	0.16 (0.07;0.30)	0.17 (0.06;0.33)	0.12 (0.00;0.53)
Wrist fracture	177	13/177	6/14	5/11	NR	NR
PPV (95% CI)		0.07 (0.04;0.12)	0.43 (0.18;0.71)	0.45 (0.17;0.77)	0.50 (0.16;0.84)	0.50 (0.12;0.88)

Note: *Admission date is the date patient is admitted to the hospital for an inpatients contact and respectively the date of visit for an outpatient contact.

Abbreviations: PPV, Positive Predictive; NR, Not reported due to small numbers.