Middlemore Hospital experience with tubo-ovarian abscesses: an observational retrospective study

Figures & data

Table 1 Overall proportion of categorical clinical risk factors and primary outcome

	N	Overall valid N	%
Resolution of TOA	140	172	0.814
Age group (years)		174
<30	35		0.201
30–39	51		0.293
40–49	75		0.431
50+	12		0.069
Gravidity 0	48	174	0.276
1	22		0.126
2	26		0.149
3	27		0.155
≥4	51		0.293
Parity 0	54	174	0.310
1	33		0.190
2	32		0.184
3	29		0.167
≥4	25		0.144
Self-reported sexually active status	143	174	0.822
History of current or pervious PID/STD	65	174	0.374
Introduction within past 3 months of IUD	2	174	0.011
Prolonged use of IUD	26	172	0.151
Recent pelvic surgery	19	174	0.109
Abdominal pain	170	174	0.977
Vaginal discharge	58	174	0.333
Fever	84	174	0.483
Cervical motion tenderness	56	174	0.322
Adnexal tenderness	84	174	0.483
Chlamydia status	12	155	0.077
Gonorrhea	2	148	0.014
Bacterial vaginosis	22	147	0.150
Bacterial culture	79	170	0.465
Bilaterality	53	173	0.306

Abbreviations: IUD, intrauterine device; PID, pelvic inflammatory disease; STD, sexually transmitted disease; TOA, tubo-ovarian abscess.

Table 2 Descriptive statistics of clinical measurements

Risk factor	Valid N	Mean	Median	Standard deviation	Minimum	Maximum	Lower quartile	Upper quartile
WBC count	174	16.1	16	5.5	4	40	12.2	19.4
Neutrophil count	174	13.4	13.2	5.4	2.4	37.2	9.8	16.6
CRP	144	152.6	147	95.6	1	386	74.5	232
Size right (cm)	95	6.9	6.9	2.6	2	16	4.8	8.6
Size left (cm)	89	6.8	6.8	2.7	1	17	4.9	8.1
Maximum size (cm)	145	7.2	7	2.6	1.5	17	5.4	8.7

Abbreviations: CRP, C-reactive protein; WBC, white blood cell.

Table 3 Microbiological results of 84 patients with TOA, including cervicovaginal swabs, blood and urine cultures, and culture of tissue or pus from abdomen showing a variety of pathogens

Bacteria	Number of cases
Streptococcus group B	14
Mixed anaerobes/genital flora	13
Chlamydia species	12
Escherichia coli	12
Actinomyces species	6
Staphyloccocus species	6
Trichomonas vaginalis	4
Bacteroides fragilis	3
Neisseria gonorrhoeae	2
Streptococcus pneumoniae	2
Streptococcus pyogenes	2
Haemophilus influenzae	2
Streptococcus Lancefield	2
Mycobacterium tuberculosis	2
Streptococcus mulliere	1
Streptococcus anginosus	1
Pasteurella multocida	1
Eikenella corrodens	1
Proteus mirabilis	1
Clostridium sporogens	1
Gardnerella vaginalis (on IUD)	1
Peptostreptococcus species	1
Fusobacterium species	1

Abbreviations: IUD, intrauterine device; TOA, tubo-ovarian abscess.

Table 4 Surgery type, team performing surgery, actual procedure performed and complications

Parameter	Laparoscopy (N=23)	Laparotomy +1 EUA (N=21)
Team performing surgery
GS	19	4
Gyn	2	11
GS + Gyn	2	6
Procedure performed
Lavage and drainage only	17	3
Excision: USO, BSO, uni- or bilateral salpingectomy, and EUA drainage of infected hematocolpos	1	11
Appendicectomy	3	2
Hysterectomy, total/subtotal, and BSO	0	5
Complications
Wound infection/dehiscence	0	6
Rectosigmoid injury	0	1a
Small bowel injury	0	1
Bladder injury	0	0
Ureteral injury	0	2
Ileus	1	0
Pneumonia	0	1
Pulmonary embolus	1	0

Note:

a The rectosigmoid was involved with endometriosis and had to be excised; patient had Hartman procedure and bowel reanastomosis later.

Abbreviations: BSO, bilateral salpingo-oophorectomy; EUA, examination under anesthesia; GS, general surgery; Gyn, gynecology; USO, unilateral salpingo-oophorectomy.

Table 5 Estimates with 95% confidence intervals, P-value, and residual deviance with degrees of freedom from the logistic regression model and normal and gamma regression models according to management plan

Outcome	Interpretation of estimates	Exposure	Estimate	95% confidence interval		P-value	Residual deviance	Degrees of freedom
Resolution of TOA	Odds ratio	Management plan: MP2 (reference category = MP1)	4.00	1.16	13.9	0.029	158.9	170
Readmission with TOA	Odds ratio	Management plan: MP2 (reference category = MP1)	0.47	0.18	1.22	0.12	179.01	170
Repeat radiology or surgical intervention	Odds ratio	Management plan: MP2 (reference category = MP1)	1.48	0.26	8.35	0.66	51.9	170
Duration of hospital stay	Relative duration	Management plan: MP2 (reference category = MP1)	1.42	1.20	1.66	<0.0001	40.3	170
Duration on antibiotics	Additive duration	Management plan MP2 (reference category = MP1)	0.13	0.059	0.19	0.0002	5.69	164

Notes: MP1= medical management plan. MP2= surgical management plan.

Abbreviations: TOA, tubo-ovarian abscess; MP, management plan.

Table 6 Odd ratios with 95% confidence intervals, overall P-value, and residual deviance with degrees of freedom for the primary outcome: resolution of TOA in each model under the grouping schedule

Model	Covariates	Odds ratio	95% confidence interval		P-value	Residual deviance	Degrees of freedom
1	Self-reported sexually active status: yes (reference category = no)	1.87	0.74	4.74	0.19	162.9	169
	History of current or previous PID/STD: yes (reference category = no)	1.50	0.65	3.43	0.34
2	Introduction within past 3 months of IUD: yes (reference category = no)	0.92	0.020	42.3	0.97	159.5	168
	Prolonged use of IUD: yes (reference category = no)	2.47	0.63	9.62	0.19
3	Recent pelvic surgery: yes (reference category = no)	4.28	0.55	33.5	0.17	162.4	170
4	Abdominal pain: yes (reference category = no)	4.60	0.62	34.0	0.13	163.2	170
5	Vaginal discharge: yes (reference category = no)	1.70	0.68	4.27	0.27	157	164
	Vaginal discharge: not stated	0.20	0.011	3.58
	Fever: yes (reference category = no)	0.82	0.36	1.84	0.62
	Cervical motion tenderness: yes (reference category = no)	0.85	0.32	2.24	0.16
	Cervical motion tenderness: not examined	11.4	0.67	193
	Adnexal tenderness: yes (reference category = no)	0.47	0.15	1.46	0.13
	Adnexal tenderness: not examined	0.065	0.004	1.04
6	WBC count (ratio)	0.88	0.64	1.21	0.43	138.2	139
	Neutrophils count (ratio)	1.07	0.77	1.49	0.69
	CRP count (ratio)^*	1.01	1.00	1.01	0.03
7	Chlamydia status: yes (reference category =no)	0.82	0.18	3.85	0.80	132.6	136
	Gonorrhoea status: yes (reference category =no)	1.21	0.027	53.6	0.92
	Bacteria vaginosis status: yes (reference category =no)	1.17	0.37	3.69	0.80
	Bacterial culture: yes (reference category =no)	2.02	0.86	4.74	0.11
8	Unilaterality or of TOA: yes (reference category =no)	0.75	0.33	1.71	0.50	161.4	169
9	Size of abscess (ratio)^*	0.79	0.67	0.92	0.0033	137.5	141

Note: The asterisk (^*) indicates that the covariates CRP count and size were found to be significant at the 5% level in model 6 and 9 respectively.

Abbreviations: IUD, intrauterine device; PID, pelvic inflammatory disease; TOA, tubo-ovarian abscess; STD, sexually transmitted disease; CRP, C-reactive protein; WBC, white blood cells.

Table 7 Odd ratios with 95% confidence intervals, overall P-value, and residual deviance with degrees of freedom for the secondary outcome: readmission with TOA in each model under the grouping schedule

Model	Covariates	Odds ratio	95% confidence interval		P-values	Residual deviance	Degrees of freedom
1	Self-reported sexually active status: yes (reference category = no)	0.96	0.37	2.45	0.92	180.7	169
	History of current or previous PID/STD: yes (reference category = no)	1.45	0.70	3.01	0.32
2	Introduction within past 3 months of IUD: yes (reference category = no)	0.85	0.019	37.6	0.93	175.8	169
	Prolonged use of IUD: yes (reference category = no)	0.49	0.15	1.61	0.24
3	Recent pelvic surgery: yes (reference category = no)	2.53	0.91	7.05	0.08	178.7	170
4	Abdominal pain: yes (reference category = no)	0.27	0.037	2.00	0.20	180.1	170
5	Vaginal discharge: yes (reference category = no)	0.92	0.42	2.04	0.30	152.0	164
	Vaginal discharge: not stated	10.23	0.52	203
	Fever: yes (reference category = no)	1.09	0.52	2.28	0.83
	Cervical motion tenderness: yes (reference category = no)	0.59	0.25	1.38	0.46
	Cervical motion tenderness: not examined	0.39	0.009	16.3
	Adnexal tenderness: yes (reference category = no)	1.89	0.75	4.74	0.36
	Adnexal tenderness: not examined	0.79	0.022	28.9
6	WBC count (ratio)	1.04	0.76	1.42	0.81	158.8	139
	Neutrophil count (ratio)	0.94	0.68	1.31	0.72
	CRP count (ratio)	1.00	1.00	1.01	0.86
7	Chlamydia status: yes (reference category = no)	0.89	0.19	4.15	0.88	147.0	136
	Gonorrhea status: yes (reference category = no)	0.82	0.019	34.4	0.92
	Bacterial vaginosis status: yes (reference category = no)	0.43	0.13	1.50	0.19
	Bacterial culture: yes (reference category = no)	0.48	0.22	1.07	0.07
8	Unilaterality or bilaterality of TOA: yes (reference category = no)	1.54	0.72	3.30	0.27	177.4	169
9	Size of abscess (ratio)	1.20	1.04	1.39	0.02*	155.1	141

Note:

* Indicates statistical significance.

Abbreviations: IUD, intrauterine device; PID, pelvic inflammatory disease; TOA, tubo-ovarian abscess; CRP, C-reactive protein; STD, sexually transmitted disease; WBC, white blood cells.

Table 8 Odd ratios with 95% confidence intervals, overall P-value, and residual deviance with degrees of freedom for the secondary outcome: repeat radiology or surgical intervention in each model under the grouping schedule

Model	Covariates	Odds ratio	95% confidence interval		P-values	Residual deviance	Degrees of freedom
1	Self-reported sexually active status: yes (reference category = no)	0.43	0.074	2.46	0.34	51	169
	History of current or previous PID/STD: yes (reference category = no)	1.57	0.30	8.11	0.59
2	Introduction within past 3 months of IUD: yes (reference category = no)	6.67	0.14	313.4	0.33	51.7	168
	Prolonged use of IUD: yes (reference category = no)	0.42	0.026	6.69	0.54
3	Recent pelvic surgery: yes (reference category = no)	1.75	0.19	15.9	0.62	51.8	170
4	Abdominal pain: yes (reference category = no)	0.092	0.008	1.05	0.055	49.5	170
5	Vaginal discharge: yes (reference category = no)	0.62	0.12	3.30	0.63	47.8	164
	Vaginal discharge: not stated	4.66	0.084	259.5
	Fever: yes (reference category = no)	0.92	0.23	3.70	0.91
	Cervical motion tenderness: yes (reference category = no)	0.15	0.01	2.23	0.29
	Cervical motion tenderness: not examined	0.031	0.0003	3.77
	Adnexal tenderness: yes (reference category = no)	0.66	0.13	3.28	0.41
	Adnexal tenderness: not examined	10.8	0.12	1001
6	WBC count (ratio)	1.05	0.68	1.63	0.83	36.6	139
	Neutrophil count (ratio)	1.12	0.71	1.75	0.63
	CRP count (ratio)	0.98	0.97	0.99	0.031*
7	Chlamydia status: yes (reference category = no)	1.27	0.066	24.5	0.87	42.6	136
	Gonorrhea status: yes (reference category = no)	3.43	0.061	193.3	0.55
	Bacterial vaginosis status: yes (reference category = no)	1.39	0.22	9.03	0.73
	Bacterial culture: yes (reference category = no)	0.37	0.066	2.11	0.27
8	Unilaterality or bilaterality of TOA: yes (reference category = no)	3.58	0.58	22.1	0.17	43.2	169
9	Size of abscess (ratio)	0.98	0.67	1.44	0.50	36.5	141

Note:

* Statistical significance.

Abbreviations: IUD, intrauterine device; CRP, C-reactive protein; PID, pelvic inflammatory disease; TOA, tubo-ovarian abscess; STD, sexually transmitted disease; WBC, white blood cells.

Table 9 Relative duration of hospital stay estimates with 95% confidence intervals in each model under the grouping schedule and according to management plan

Model	Covariates	Relative duration	95% confidence interval		P-value	Residual deviance	Degrees of freedom	Dispersion parameter
1	Self-reported sexually active status: yes (reference category = no)	0.71	0.59	0.86	0.001*	38.9	166	0.234
	History of current or previous PID/STD: yes (reference category = no)	1.13	0.97	1.31	0.11
	Age group: 30–39 years (reference category =12–29 years)	1.08	0.88	1.32	0.21
	Age group: 40–49 years (reference category =12–29 years)	1.22	1.01	1.48
	Age group: 50+ years (reference category =12–29 years)	1.18	0.86	1.62
2	Introduction within past 3 months of IUD: yes (reference category = no)	0.80	0.41	1.58	0.54	40.9	165	0.248
	Prolonged use of IUD: yes (reference category = no)	0.85	0.69	1.05	0.14
	Age group: 30–39 years (reference category =12–29 years)	1.11	0.90	1.37	0.023
	Age group: 40–49 years (reference category =12–29 years)	1.34	1.10	1.63
	Age group: 50+ years (reference category =12–29 years)	1.29	0.94	1.77
3	Recent pelvic surgery: yes (reference category = no)	1.11	0.87	1.41	0.41	42.4	167	0.254
	Age group: 30–39 years (reference category =12–29 years)	1.07	0.87	1.32	0.049
	Age group: 40–49 years (reference category =12–29 years)	1.28	1.05	1.56
	Age group: 50+ years (reference category =12–29 years)	1.28	0.93	1.76
4	Abdominal pain: yes (reference category = no)	0.97	0.59	1.57	0.89	42.6	167	0.255
	Age group: 30–39 years (reference category =12–29 years)	1.08	0.88	1.34	0.058
	Age group: 40–49 years (reference category =12–29 years)	1.28	1.05	1.56
	Age group: 50+ years (reference category =12–29 years)	1.28	0.93	1.76
5	Vaginal discharge: yes (reference category = no)	0.96	0.82	1.12	0.85	39.1	161	0.243
	Vaginal discharge: not stated	0.92	0.47	1.79
	Fever: yes (reference category = no)	1.34	1.16	1.55	0.0001*
	Cervical motion tenderness: yes (reference category = no)	0.99	0.83	1.18	0.67
	Cervical motion tenderness: not examined	1.29	0.71	2.33
	Adnexal tenderness: yes (reference category = no)	0.97	0.81	1.18	0.78
	Adnexal tenderness: not examined	0.81	0.45	1.44
	Age group: 30–39 years (reference category =12–29 years)	1.08	0.88	1.33	0.077
	Age group: 40–49 years (reference category =12–29 years)	1.26	1.04	1.52
	Age group: 50+ years (reference category =12–29 years)	1.24	0.91	1.69
6	WBC count (ratio)	1.04	0.98	1.10	0.21	28.1	136	0.206
	Neutrophil count (ratio)	0.98	0.92	1.04	0.44
	CRP count (ratio)	1.0015	1.0007	1.0024	0.0003*
	Age group: 30–39 years (reference category =12–29 years)	1.15	0.93	1.43	0.49
	Age group: 40–49 years (reference category =12–29 years)	1.13	0.93	1.38
	Age group: 50+ years (reference category =12–29 years)	1.24	0.91	1.70
7	Chlamydia status: yes (reference category = no)	0.92	0.67	1.26	0.61	33.4	133	0.251
	Gonorrhea status: yes (reference category = no)	0.88	0.45	1.73	0.71
	Bacterial vaginosis status: yes (reference category = no)	0.86	0.69	1.08	0.22
	Bacterial culture: yes (reference category = no)	1.07	0.91	1.26	0.39
	Age group: 30–39 years (reference category =12–29 years)	1.20	0.95	1.52	0.13
	Age group: 40–49 years (reference category =12–29 years)	1.31	1.05	1.64
	Age group: 50+ years (reference category =12–29 years)	1.26	0.82	1.93
8	Unilaterality or bilaterality of TOA: yes (reference category = no)	1.35	1.16	1.58	0.0002*	39.3	166	0.237
	Age group: 30–39 years (reference category =12–29 years)	1.08	0.89	1.33	0.0074
	Age group: 40–49 years (reference category =12–29 years)	1.34	1.10	1.62
	Age group: 50+ years (reference category =12–29 years)	1.43	1.04	1.95
9	Size of abscess (ratio)	1.06	1.03	1.09	<0.0001*	28.2	138	0.204
	Age group: 30–39 years (reference category =12–29 years)	0.93	0.75	1.15	0.18
	Age group: 40–49 years (reference category =12–29 years)	1.12	0.92	1.37
	Age group: 50+ years (reference category =12–29 years)	1.07	0.79	1.46
10	Relative duration of hospital stay estimates with 95% confidence intervals according to management plan adjusted by age group
	Management plan (reference category = MP1)	1.45	1.24	1.70	<0.0001	37.9	167	0.227
	Age group: 30–39 years (reference category =12–29 years)	1.12	0.92	1.37	0.012*
	Age group: 40–49 years (reference category =12–29 years)	1.33	1.10	1.60
	Age group: 50+ years (reference category =12–29 years)	1.40	1.03	1.90

Notes: The coefficient estimates from these models were back transformed to get the estimated relative duration.

* Statistical significance. MP1= medical management plan.

Abbreviations: CRP, C-reactive protein; IUD, intrauterine device; PID, pelvic inflammatory disease; TOA, tubo-ovarian abscess; STD, sexually transmitted disease; WBC, white blood cells; MP, management plan.